YOSHINOBU NAKATANI
| Department of Computer and Network Engineering | Professor |
| Cluster I (Informatics and Computer Engineering) | Professor |
Researcher Information
Research Activity Information
Paper
- Influence of different imaging scales on machine learning-based determination of magnetic parameters from magnetic images
Akito Watanabe; Yoshinobu Nakatani; Hiroyuki Awano; Kenji Tanabe
Applied Physics Letters, AIP Publishing, 126, 23, 09 Jun. 2025, The determination of material parameters is significantly important in material science, which is often a challenging task. Recently, advancements have shown that magnetic parameters, such as the Dzyaloshinskii–Moriya interaction (DMI), can be estimated from a magnetic domain image using machine learning (ML). This development suggests a potential shift in how magnetic parameters are determined, moving away from traditional measurement techniques to more innovative methods involving image-based inputs processed by ML. In previous studies, the test images used for estimation always matched the training images in size. However, since the image size is contingent on the microscopy technique used, the ability to accurately estimate parameters from images of varying sizes is essential. Here, we investigated the feasibility of estimating the DMI constant and saturation magnetization from magnetic domain images of different sizes using ML. We demonstrated that it is possible to estimate these parameters even when the imaging sizes differ between training and test datasets. Additionally, our comparison of the estimation accuracy for the DMI constant and saturation magnetization revealed that the tolerance for differences in the image size varies depending on the specific parameter being estimated. These findings could have a significant impact on the future methods of determining magnetic parameters.
Scientific journal - Current-driven fast magnetic octupole domain-wall motion in noncollinear antiferromagnets
Mingxing Wu; Taishi Chen; Takuya Nomoto; Yaroslav Tserkovnyak; Hironari Isshiki; Yoshinobu Nakatani; Tomoya Higo; Takahiro Tomita; Kouta Kondou; Ryotaro Arita; Satoru Nakatsuji; Yoshichika Otani
Nature Communications, Springer Science and Business Media LLC, 15, 1, 11 Jun. 2024, Peer-reviwed, Abstract
Antiferromagnets (AFMs) have the natural advantages of terahertz spin dynamics and negligible stray fields, thus appealing for use in domain-wall applications. However, their insensitive magneto-electric responses make controlling them in domain-wall devices challenging. Recent research on noncollinear chiral AFMs Mn3X (X = Sn, Ge) enabled us to detect and manipulate their magnetic octupole domain states. Here, we demonstrate a current-driven fast magnetic octupole domain-wall (MODW) motion in Mn3X. The magneto-optical Kerr observation reveals the Néel-like MODW of Mn3Ge can be accelerated up to 750 m s-1 with a current density of only 7.56 × 1010 A m-2 without external magnetic fields. The MODWs show extremely high mobility with a small critical current density. We theoretically extend the spin-torque phenomenology for domain-wall dynamics from collinear to noncollinear magnetic systems. Our study opens a new route for antiferromagnetic domain-wall-based applications.
Scientific journal - Reducing switching current with Gilbert damping constant in nanomagnets with perpendicular anisotropy under Dzyaloshinskii–Moriya interaction
Keisuke Yamada; Shun-ichi Takamatsu; Hiroki Asakawa; Yoshinobu Nakatani
Last, Applied Physics Express, IOP Publishing, 16, 11, 113001-113001, 01 Nov. 2023, Abstract
We report current-induced magnetization switching (jsw) with a nanosecond-duration pulse current (tp) in a perpendicularly magnetized nanomagnet under the Dzyaloshinskii–Moriya interaction (DMI) and investigate the effect of the Gilbert damping constant (α), tp, and DMI value (D) on jsw via micromagnetic simulations. When α is sufficiently small at tp = 1 ns, jsw for D = 1.0 erg cm−2 decreases by 42% compared to that for D = 0 erg cm−2. Further, jsw can be reduced under the DMI when α is small and tp is short, which is attributed to the twisted magnetization and increased initial magnetization angle.
Scientific journal - Magnetic octupole domain evolution and domain-wall structure in the noncollinear Weyl antiferromagnet Mn3Ge
Mingxing Wu; Kouta Kondou; Yoshinobu Nakatani; Taishi Chen; Hironari Isshiki; Tomoya Higo; Satoru Nakatsuji; Yoshichika Otani
APL Materials, AIP Publishing, 11, 8, 01 Aug. 2023, Peer-reviwed, Antiferromagnets with the intrinsic advantages of terahertz spin dynamics and negligible stray fields have been extensively studied for spintronic applications. In particular, spintronic research on antiferromagnets has expanded its focus from collinear to noncollinear Weyl antiferromagnets and discovered that Mn3X (X = Sn, Ge) produces substantial magneto-electric responses. Therefore, noncollinear antiferromagnets could be an ideal spintronic platform. Exploring the domain-wall features in Mn3X is, on the other hand, essential for spintronic device engineering. Here, we report an in-depth study on magnetic octupole domain evolution and domain-wall structure with a choice of Mn3Ge single crystal. Our magneto-optical imaging and the anomalous Hall measurements elucidate the nontrivial magnetic octupole domain nucleation, domain-wall propagation, and pinning behaviors. Moreover, combining the micromagnetic simulation, we reveal that Bloch- and Néel-like walls coexist in bulk with comparable sizes and energy densities. Our findings promote understanding the magnetic octupole domain-wall physics and designing domain-wall-based spintronic devices.
Scientific journal - Effects of structure, size and non-magnetic Cu layer thickness on magnetization switching behavior in Ni/Cu/M (M
Keisuke Yamada; Mayu Kikuchi; Anissa Binti Azizan; Yuuna Tsuchiya; Shota Ono; Yoshinobu Nakatani; Mutsuhiro Shima
Nano-Structures & Nano-Objects, Elsevier BV, 35, 101012-101012, Jul. 2023, Peer-reviwed
Scientific journal, English - Simulation of spin-orbit-torque switching of a perpendicular nanomagnet assisted by DMI
Joshiro Watanabe; Keisuke Yamada; Yoshinobu Nakatani
Last, IEEE Transactions on Magnetics, Institute of Electrical and Electronics Engineers (IEEE), 59, 11, 1-1, Jun. 2023, Peer-reviwed
Scientific journal, English - Elucidation of the mechanism for maintaining ultrafast domain wall mobility over a wide temperature range
S. Ranjbar; S. Kambe; S. Sumi; P. Thach; Y. Nakatani; K. Tanabe; H. Awano
MATERIALS ADVANCES, 3, 18, 7028-7036, Sep. 2022, Peer-reviwed
Scientific journal, English - Adjacent Track Interference in Heat-Assisted Magnetic Recording
T. Kobayashi; Y. Nakatani; Y. Fujiwara
Journal of the Magnetics Society of Japan, 46, 3, 49-57, May 2022, Peer-reviwed
Scientific journal - Chirality-induced effective field in Pt/Co/MgO system with spatial anisotropy-modulation
T. Koyama; Y. Nakatani; D. Chiba
Applied Physics Letters, AIP Publishing, 120, 17, 172402-172402, 25 Apr. 2022, Peer-reviwed, In a perpendicularly magnetized (PM) material with the interfacial Dzyaloshinskii–Moriya interaction (iDMI), a chirality-induced effective magnetic field (EMF) acts on a magnetic domain wall, which is a naturally formed in-plane magnetized (IM) region sandwiched by perpendicular (PM) regions. In this study, we artificially created a Pt/Co/MgO system with the regions exhibiting different anisotropy, that is, IM and PM regions, and the chirality-induced EMF at the PM/IM boundary was investigated using it. The EMF in the IM region was probed using magnetoresistance (MR) measurements. When the field was applied orthogonally to the wire, a unidirectional shift of the MR curve was observed, indicating that the EMF exists in the IM region. The dependence of the EMF on the width of the IM region suggests that the EMF acts dominantly on the magnetization near the PM/IM boundary. Moreover, the sign of the shift is reversed with reversing the PM direction. The sign and magnitude of the EMF observed in this study suggest that the EMF in the present system is caused by iDMI.
Scientific journal - Information Degradation during Archiving in Heat-Assisted Magnetic Recording
T. Kobayashi; Y. Nakatani; Y. Fujiwara
Journal of the Magnetics Society of Japan, 46, 1, 10-15, Jan. 2022, Peer-reviwed
Scientific journal - Discrimination of skyrmion chirality via spin-orbit and -transfer torques for logic operation.
Yoshinobu Nakatani; Keisuke Yamada; Atsufumi Hirohata
Scientific reports, 11, 1, 8415-8415, 16 Apr. 2021, Peer-reviwed, True
Scientific journal, English - Medium layer structure in three-dimensional heat-assisted magnetic recording
T. Kobayashi; Y. Nakatani; Y. Fujiwara
Journal of the Magnetics Society of Japan, 45, 2, 16-24, 01 Mar. 2021, Peer-reviwed
Scientific journal - Adjacent track interference in three-dimensional heat-assisted magnetic recording
T. Kobayashi; Y. Nakatani; Y. Fujiwara
Journal of the Magnetics Society of Japan, 45, 4, 79-85, 2021, Peer-reviwed
Scientific journal - Determination of the Dzyaloshinskii-Moriya interaction using pattern recognition and machine learning
Masashi Kawaguchi; Kenji Tanabe; Keisuke Yamada; Takuya Sawa; Shun Hasegawa; Masamitsu Hayashi; Yoshinobu Nakatani
NPJ COMPUTATIONAL MATERIALS, 7, 1, Jan. 2021, Peer-reviwed
Scientific journal, English - Control of current-induced skyrmion motion in ratchet-type skyrmion-based racetrack memory with a loop structure
Riki Yamaguchi; Keisuke Yamada; Yoshinobu Nakatani
JAPANESE JOURNAL OF APPLIED PHYSICS, 60, 1, Jan. 2021, Peer-reviwed
Scientific journal, English - Electrical nucleation, displacement, and detection of antiferromagnetic domain walls in the chiral antiferromagnet Mn3Sn
Satoshi Sugimoto; Yoshinobu Nakatani; Yuta Yamane; Muhammad Ikhlas; Kouta Kondou; Motoi Kimata; Takahiro Tomita; Satoru Nakatsuji; Yoshichika Otani
Communications Physics, 3, 1, Dec. 2020, Peer-reviwed
Scientific journal, English - Review on spintronics: Principles and device applications
Atsufumi Hirohata; Keisuke Yamada; Yoshinobu Nakatani; Ioan-Lucian Prejbeanu; Bernard Diény; Philipp Pirro; Burkard Hillebrands
Journal of Magnetism and Magnetic Materials, 509, 166711-166711, Sep. 2020, Peer-reviwed
Scientific journal, English - Thermally consistent SPICE model for magnetic tunnel junction with multi-layered structures via interlayer interaction
Ken Machida; Yasuyuki Kayama; Yoshinobu Nakatani
JAPANESE JOURNAL OF APPLIED PHYSICS, 59, 6, Jun. 2020, Peer-reviwed
Scientific journal, English - Information Stability in Three-Dimensional Heat-Assisted Magnetic Recording
T. Kobayashi; Y. Nakatani; Y. Fujiwara
J. Magn. Soc. Jpn., 44, 2, 34-39, Mar. 2020, Peer-reviwed
Scientific journal, English - Media design for three-dimensional heat-assisted magnetic recording
T. Kobayashi; Y. Nakatani; Y. Fujiwara
Journal of the Magnetics Society of Japan, 44, 5, 122-128, 2020
Scientific journal - Information Stability in Heat-Assisted Magnetic Recording
T. Kobayashi; Y. Nakatani; Y. Fujiwara
J. Magn. Soc. Jpn., 43, 6, 114-119, Nov. 2019, Peer-reviwed
Scientific journal, English - Switching of Skyrmion chirality by local heating
Y. Nakatani; K. Yamada; A. Hirohata
Scientific Reports, 9, 1, 13475-13475, Sep. 2019, Peer-reviwed, True
Scientific journal, English - Voltage-controlled magnetic skyrmions in magnetic tunnel junctions
Shinya Kasai; Satoshi Sugimoto; Yoshinobu Nakatani; Ryo Ishikawa; Yukiko K. Takahashi
APPLIED PHYSICS EXPRESS, 12, 8, Aug. 2019
Scientific journal, English - Impact of Curie Temperature Variation on Bit Error Rate in Heat-Assisted Magnetic Recording
T. Kobayashi; Y. Nakatani; Y. Fujiwara
J. Magn. Soc. Jpn., 43, 4, 70-78, Jul. 2019, Peer-reviwed
Scientific journal, English - Current-Induced Modulation of the Interfacial Dzyaloshinskii-Moriya Interaction.
Naoaki Kato; Masashi Kawaguchi; Yong-Chang Lau; Toru Kikuchi; Yoshinobu Nakatani; Masamitsu Hayashi
Physical review letters, 122, 25, 257205-257205, 28 Jun. 2019, True
Scientific journal, English - Critical current formula of perpendicularly magnetized magnetic random access memory revisited
Taniguchi Tomohiro; Yamada Keisuke; Nakatani Yoshinobu
JAPANESE JOURNAL OF APPLIED PHYSICS, 58, 5, 01 May 2019, Peer-reviwed
Scientific journal, English - Understanding Signal-to-Noise Ratio in Heat-Assisted Magnetic Recording
T. Kobayashi; Y. Nakatani; Y. Fujiwara
J. Magn. Soc. Jpn., 42, 6, 127-137, Nov. 2018, Peer-reviwed
Scientific journal, English - Magnetic domain wall motion in anti-ferromagnetic nanowires induced by sloped electric field
K. Yamada; K. Kubota; Y. Nakatani
Appl. Phys. Express, 11, 11, 113001, 2018, Peer-reviwed
Scientific journal, English - Writing Field Sensitivity in Heat-Assisted Magnetic Recording
T. Kobayashi; Y. Nakatani; Y. Fujiwara
J. Magn. Soc. Jpn., 42, pp. 110-118, 2018, Peer-reviwed - Domain-wall resistance in CoFeB-based heterostructures with interface Dzyaloshinski-Moriya interaction
Y. Ishikuro; M, Kawaguchi; Y.-C. Lau; Y. Nakatani; M. Hayashi
Appl. Phys. Express, 11, 7, 73001, 2018, Peer-reviwed
Scientific journal, English - Writing Field Amplitude in Heat-Assisted Magnetic Recording
T. Kobayashi; Y. Nakatani; K. Enomoto; Y. Fujiwara
J. Magn. Soc. Jpn., 42, pp. 15-19, 2018, Peer-reviwed - Numerical Study on a Novel Curie Temperature Controlled Hybrid Thermo-Magnetic Structure for Magnetic Random Access Memories
Ken Machida; Yoshiaki Sonobe; Yoshinobu Nakatani
IEEE TRANSACTIONS ON MAGNETICS, 53, 11, article number 2002205, Nov. 2017, Peer-reviwed
Scientific journal, English - Examination of the stability of skyrmion structures in perpendicularly-magnetized Co/Ni films
Keisuke Yamada; Shigeru Hozumi; Yoshinobu Nakatani
JAPANESE JOURNAL OF APPLIED PHYSICS, 56, 5, 50309, May 2017, Peer-reviwed
Scientific journal, English - Energy-efficient writing scheme for magnetic domain-wall motion memory
Kab-Jin Kim; Yoko Yoshimura; Woo Seung Ham; Rick Ernst; Yuushou Hirata; Tian Li; Sanghoon Kim; Takahiro Moriyama; Yoshinobu Nakatani; Teruo Ono
APPLIED PHYSICS EXPRESS, 10, 4, 43002, Apr. 2017, Peer-reviwed
Scientific journal, English - Impact of Damping Constant on Bit Error Rate in Heat-Assisted Magnetic Recording
T. Kobayashi; Y. Nakatani; F. Inukai; K. Enomoto; Y. Fujiwara
J. Magn. Soc. Jpn., The Magnetics Society of Japan, 41, 3, pp. 52-57-57, 2017, Peer-reviwed,We calculate the writing field dependence of the bit error rate for Gilbert damping constants of 0.1 and 0.01 in heat-assisted magnetic recording (HAMR) using a new model calculation. The attempt period used in the new model calculation is considered in detail. The writing properties are examined for various thermal gradients, linear velocities, and anisotropy constants. When the damping constant is equal to 0.1, write-error is smaller, and erasure-after-write is larger than that for 0.01 since the attempt period is short. The physical implication of the results is discussed. We also compare the results of the new model calculation and the conventionally used micromagnetic calculation. The overall tendencies of the results are the same. Therefore, the outline of the impact of the damping constant on the bit error rate in HAMR can be understood by the grain magnetization reversal probability and the attempt period used in the new model calculation.
English - Magnetic domain wall motion in Co/Ni nanowires induced by a sloped electric field
Keisuke Yamada; Soh Murayama; Yoshinobu Nakatani
APPLIED PHYSICS LETTERS, 108, 20, 202405, May 2016, Peer-reviwed
Scientific journal, English - Depinning field of domain walls with a misaligned grain boundary in iron-based soft magnets
Keisuke Yamada; Shota Irie; Soh Murayama; Yoshinobu Nakatani
APPLIED PHYSICS EXPRESS, 9, 5, 53003, May 2016, Peer-reviwed
Scientific journal, English - Electric field control of Skyrmions in magnetic nanodisks
Y. Nakatani; M. Hayashi; S. Kanai; S. Fukami; H. Ohno
APPLIED PHYSICS LETTERS, 108, 15, 152403, Apr. 2016, Peer-reviwed
Scientific journal, English - Observation of asymmetry in domain wall velocity under transverse magnetic field
K. -J. Kim; Y. Yoshimura; T. Okuno; T. Moriyama; S. -W. Lee; K. -J. Lee; Y. Nakatani; T. Ono
APL MATERIALS, 4, 3, 32504, Mar. 2016, Peer-reviwed
Scientific journal, English - Soliton-like magnetic domain wall motion induced by the interfacial Dzyaloshinskii-Moriya interaction
Yoko Yoshimura; Kab-Jin Kim; Takuya Taniguchi; Takayuki Tono; Kohei Ueda; Ryo Hiramatsu; Takahiro Moriyama; Keisuke Yamada; Yoshinobu Nakatani; Teruo Ono
NATURE PHYSICS, 12, 2, 157-+, Feb. 2016, Peer-reviwed
Scientific journal, English - Reducing the switching current with a Gilbert damping constant in nanomagnets with perpendicular anisotropy (vol 106, 042402, 2015)
Keisuke Yamada; Kiyoaki Oomaru; Satoshi Nakamura; Tomonori Sato; Yoshinobu Nakatani
APPLIED PHYSICS LETTERS, 108, 5, Feb. 2016, Peer-reviwed
English - Magnetization switching by current and microwaves
Tomohiro Taniguchi; Daisuke Saida; Yoshinobu Nakatani; Hitoshi Kubota
PHYSICAL REVIEW B, 93, 1, 14430, Jan. 2016, Peer-reviwed
Scientific journal, English - 19aAU-8 Soliton-like magnetic domain wall motion induced by the interfacial Dzyaloshinskii-Moriya interaction
Yoshimura Yoko; Kim Kab-Jin; Taniguchi Takuya; Tono Takayuki; Ueda Kohei; Hiramatsu Ryo; Moriyama Takahiro; Yamada Keisuke; Nakatani Yoshinobu; Ono Teruo
Meeting Abstracts of the Physical Society of Japan, The Physical Society of Japan (JPS), 71, 1003-1003, 2016
Japanese - 19pPSB-53 Computer simulation of domain wall motion induced by a slope electric field and DMI
Murayama Soh; Yamada Keisuke; Nakatani Yoshinobu
Meeting Abstracts of the Physical Society of Japan, The Physical Society of Japan (JPS), 71, 1179-1179, 2016
Japanese - 19pPSB-51 Effect of the Gilbert damping constant of the switching current in Exchange-coupled composite type Spin-RAM
Takizawa Ryoto; Yamada Keisuke; Nakatani Yoshinobu
Meeting Abstracts of the Physical Society of Japan, The Physical Society of Japan (JPS), 71, 1177-1177, 2016
Japanese - 19pPSB-52 Effect of Gilbert damping constant on the domain wall pinning in permanent magnets
Kitajima Akimitsu; Yamada Keisuke; Nakatani Yoshinobu
Meeting Abstracts of the Physical Society of Japan, The Physical Society of Japan (JPS), 71, 1178-1178, 2016
Japanese - Excitation of magnetic domain wall velocity in (Co/Ni) nanowires induced by blocking the motion of vertical Bloch lines
Keisuke Yamada; Yoshinobu Nakatani
APPLIED PHYSICS EXPRESS, 8, 9, 93004, Sep. 2015, Peer-reviwed
Scientific journal, English - Precise control of magnetic domain wall displacement by a nanosecond current pulse in Co/Ni nanowires
Takuya Taniguchi; Kab-Jin Kim; Takayuki Tono; Takahiro Moriyama; Yoshinobu Nakatani; Teruo Ono
APPLIED PHYSICS EXPRESS, 8, 7, 73008, Jul. 2015, Peer-reviwed
Scientific journal, English - Localized precessional mode of domain wall controlled by magnetic field and dc current
Ryo Hiramatsu; Kab-Jin Kim; Takuya Taniguchi; Takayuki Tono; Takahiro Moriyama; Shunsuke Fukami; Michihiko Yamanouchi; Hideo Ohno; Yoshinobu Nakatani; Teruo Ono
APPLIED PHYSICS EXPRESS, 8, 2, 23003, Feb. 2015, Peer-reviwed
Scientific journal, English - Reducing the switching current with a Gilbert damping constant in nanomagnets with perpendicular anisotropy
Keisuke Yamada; Kiyoaki Oomaru; Satoshi Nakamura; Tomonori Sato; Yoshinobu Nakatani
APPLIED PHYSICS LETTERS, 106, 4, 42402, Jan. 2015, Peer-reviwed
Scientific journal, English - 18pCM-10 Effect of the Gilbert damping constant on the switching current in the spin-transfer switching with the thermal fluctuation interaction
Yamada Keisuke; Nakatani Yoshinobu
Meeting Abstracts of the Physical Society of Japan, The Physical Society of Japan (JPS), 70, 963-963, 2015
Japanese - 18pCM-1 Domain wall manipulation by nanosecond pulse current
Taniguchi T.; Kim K.-J.; Tono T.; Moriyama T.; Nakatani Y.; Ono T.
Meeting Abstracts of the Physical Society of Japan, The Physical Society of Japan (JPS), 70, 954-954, 2015
Japanese - 23pAD-3 Simulation of the field-driven magnetic domain wall motion under the Dzyaloshinskii-Moriya interaction
Yamada Keisuke; Nakatani Yoshinobu
Meeting Abstracts of the Physical Society of Japan, The Physical Society of Japan (JPS), 70, 1198-1198, 2015
Japanese - 23pAD-1 Magnetic domain-wall oscillator controlled by magnetic field and dc current
Hiramatsu R.; Kim Kab-Jin; Taniguchi T.; Tono T.; Moriyama T.; Fukami S.; Yamanouchi M.; Ohno H.; Nakatani Y.; Ono T.
Meeting Abstracts of the Physical Society of Japan, The Physical Society of Japan (JPS), 70, 1196-1196, 2015
Japanese - 22pAH-12 Detection of Magnetic Vortex Core by the Ballistic Microstructure
Tanaka T.; Kawamura T.; Arakawa T.; Tanabe K.; Kobayashi K.; Yamada K.; Nakatani Y.; Ono T.
Meeting Abstracts of the Physical Society of Japan, The Physical Society of Japan (JPS), 70, 1193-1193, 2015
Japanese - Proposal for quantifying the Dzyaloshinsky-Moriya interaction by domain walls annihilation measurement
Ryo Hiramatsu; Kab-Jin Kim; Yoshinobu Nakatani; Takahiro Moriyama; Teruo Ono
JAPANESE JOURNAL OF APPLIED PHYSICS, 53, 10, 108001, Oct. 2014, Peer-reviwed
Scientific journal, English - Coupled oscillations of vortex cores confined in a ferromagnetic elliptical disk
Hiroshi Hata; Minori Goto; Akinobu Yamaguchi; Tomonori Sato; Yoshinobu Nakatani; Yukio Nozaki
PHYSICAL REVIEW B, 90, 10, 104418, Sep. 2014, Peer-reviwed
Scientific journal, English - Control of magnetic vortex core switching in a Pac-man disk using a single current pulse
Tomonori Sato; Keisuke Yamada; Yoshinobu Nakatani
APPLIED PHYSICS EXPRESS, 7, 7, 73003, Jul. 2014, Peer-reviwed
Scientific journal, English - Switching of magnetic vortex core in elliptical disks by nanosecond field pulses
Keisuke Yamada; Tomonori Sato; Yoshinobu Nakatani; Shinya Kasai; Daichi Chiba; Kensuke Kobayashi; Andre Thiaville; Teruo Ono
APPLIED PHYSICS EXPRESS, 7, 6, 63008, Jun. 2014, Peer-reviwed
Scientific journal, English - Magnetization switching in a CoFeB/MgO magnetic tunnel junction by combining spin-transfer torque and electric field-effect
S. Kanai; Y. Nakatani; M. Yamanouchi; S. Ikeda; H. Sato; F. Matsukura; H. Ohno
APPLIED PHYSICS LETTERS, 104, 21, 212406, May 2014, Peer-reviwed
Scientific journal, English - Spin-transfer torque magnetoresistive random-access memory technologies for normally off computing (invited)
K. Ando; S. Fujita; J. Ito; S. Yuasa; Y. Suzuki; Y. Nakatani; T. Miyazaki; H. Yoda
JOURNAL OF APPLIED PHYSICS, 115, 17, 172607, May 2014, Peer-reviwed
Scientific journal, English - Distribution of critical current density for magnetic domain wall motion
S. Fukami; M. Yamanouchi; Y. Nakatani; K. -J. Kim; T. Koyama; D. Chiba; S. Ikeda; N. Kasai; T. Ono; H. Ohno
JOURNAL OF APPLIED PHYSICS, 115, 17, 17D508, May 2014, Peer-reviwed
Scientific journal, English - Effect of spin Hall torque on current-induced precessional domain wall motion
Yoko Yoshimura; Tomohiro Koyama; Daichi Chiba; Yoshinobu Nakatani; Shunsuke Fukami; Michihiko Yamanouchi; Hideo Ohno; Kab-Jin Kim; Takahiro Moriyama; Teruo Ono
APPLIED PHYSICS EXPRESS, 7, 3, 33005, Mar. 2014, Peer-reviwed
Scientific journal, English - Switching of magnetic vortex core in a Pac-man disk using a single field pulse
Tomonori Sato; Keisuke Yamada; Yoshinobu Nakatani
APPLIED PHYSICS EXPRESS, 7, 3, 33003, Mar. 2014, Peer-reviwed
Scientific journal, English - Electric Field-Induced Magnetization Switching in CoFeB-MgO-Static Magnetic Field Angle Dependence
Shun Kanai; Michihiko Yamanouchi; Shoji Ikeda; Yoshinobu Nakatani; Fumihiro Matsukura; Hideo Ohno
IEEE TRANSACTIONS ON MAGNETICS, 50, 1, article number 4200103, Jan. 2014, Peer-reviwed
Scientific journal, English - IEEE Transactions on Magnetics
S. Kanai; M. Yamanouchi; S. Ikeda; Y. Nakatani; F. Matsukura; H. Ohno
Electric field-induced magnetization switching in CoFeB-MgO-static magnetic field angle dependence, 50, 1, 4200103(1)-4200103(3), Jan. 2014, Peer-reviwed
Scientific journal, English - Micromagnetics of Domain Wall Dynamics in Soft Nanostrips
André Thiaville; Yoshinobu Nakatani
Nanomagnetism and Spintronics: Second Edition, Elsevier Inc., 261-313, Oct. 2013, Peer-reviwed
In book, English - Applied Physics Letters
S. Kanai; Y. Nakatani; M. Yamanouchi; S. Ikeda; F. Matsukura; H. Ohno
In-plane magnetic field dependence of electric field-induced magnetization switching, 103, 072408(1)-072408(4), 16 Aug. 2013, Peer-reviwed
Scientific journal, English - In-plane magnetic field dependence of electric field-induced magnetization switching
S. Kanai; Y. Nakatani; M. Yamanouchi; S. Ikeda; F. Matsukura; H. Ohno
APPLIED PHYSICS LETTERS, 103, 7, 72408, Aug. 2013, Peer-reviwed
Scientific journal, English - Nature Communications
K. J. Kim; R. Hiramatsu; T. Koyama; K. Ueda; Y. Yoshimura; D. Chiba; K. Kobayashi; Y. Nakatani; S. Fukami; M. Yamanouchi; H. Ohno; H. Kohno; G. Tatara; T. Ono
Two-barrier stability that allows low-power operation in current-induced domain-wall motion, 4, 1-6, 17 Jun. 2013, Peer-reviwed
Scientific journal, English - Static and dynamic behavior of 360 degrees domain walls in patterned thin films
A. L. Gonzalez Oyarce; Y. Nakatani; C. H. W. Barnes
PHYSICAL REVIEW B, 87, 21, 214403, Jun. 2013, Peer-reviwed
Scientific journal, English - Two-barrier stability that allows low-power operation in current-induced domain-wall motion
Kab-Jin Kim; Ryo Hiramatsu; Tomohiro Koyama; Kohei Ueda; Yoko Yoshimura; Daichi Chiba; Kensuke Kobayashi; Yoshinobu Nakatani; Shunsuke Fukami; Michihiko Yamanouchi; Hideo Ohno; Hiroshi Kohno; Gen Tatara; Teruo Ono
NATURE COMMUNICATIONS, 4, Article number 2011-2011, Jun. 2013, Peer-reviwed, True
Scientific journal, English - Current-Induced Magnetic Domain Wall Motion in a Co/Ni Nanowire with Structural Inversion Asymmetry
Tomohiro Koyama; Hiroshi Hata; Kab-Jin Kim; Takahiro Moriyama; Hironobu Tanigawa; Tetsuhiro Suzuki; Yoshinobu Nakatani; Daichi Chiba; Teruo Ono
APPLIED PHYSICS EXPRESS, 6, 3, 33001, Mar. 2013, Peer-reviwed
Scientific journal, English - Real-time observation of electrical vortex core switching
Kunihiro Nakano; Kenji Tanabe; Ryo Hiramatsu; Daichi Chiba; Norikazu Ohshima; Shinya Kasai; Tomonori Sato; Yoshinobu Nakatani; Koji Sekiguchi; Kensuke Kobayashi; Teruo Ono
APPLIED PHYSICS LETTERS, 102, 7, 72405, Feb. 2013, Peer-reviwed
Scientific journal, English - Recording Density Limitation Explored by Head/Media Co-Optimization Using Genetic Algorithm and GPU-Accelerated LLG
Hiroshi Fukuda; Yoshinobu Nakatani
IEEE TRANSACTIONS ON MAGNETICS, 48, 11, 3895-3898, Nov. 2012, Peer-reviwed
Scientific journal, English - Current-induced magnetic domain wall motion below intrinsic threshold triggered by Walker breakdown
T. Koyama; K. Ueda; K. -J. Kim; Y. Yoshimura; D. Chiba; K. Yamada; J. -P. Jamet; A. Mougin; A. Thiaville; S. Mizukami; S. Fukami; N. Ishiwata; Y. Nakatani; H. Kohno; K. Kobayashi; T. Ono
NATURE NANOTECHNOLOGY, 7, 10, 635-639, Oct. 2012, Peer-reviwed
Scientific journal, English - Symmetry breaking in the formation of magnetic vortex states in a permalloy nanodisk
Mi-Young Im; Peter Fischer; Keisuke Yamada; Tomonori Sato; Shinya Kasai; Yoshinobu Nakatani; Teruo Ono
NATURE COMMUNICATIONS, 3, Article number 983-983, Jul. 2012, Peer-reviwed, True
Scientific journal, English - Switching time of a single spin in linearly varying field
Yasutaro Uesaka; Yoshio Suzuki; Osamu Kitakami; Yoshinobu Nakatani; Nobuo Hayashi; Hiroshi Fukushima
JOURNAL OF APPLIED PHYSICS, 111, 12, 123907, Jun. 2012, Peer-reviwed
Scientific journal, English - Current-Induced Domain Wall Motion in Perpendicularly Magnetized Co/Ni Nanowire under In-Plane Magnetic Fields
Yoko Yoshimura; Tomohiro Koyama; Daichi Chiba; Yoshinobu Nakatani; Shunsuke Fukami; Michihiko Yamanouchi; Hideo Ohno; Teruo Ono
APPLIED PHYSICS EXPRESS, 5, 6, 63001, Jun. 2012, Peer-reviwed
Scientific journal, English - Temperature dependence of carrier spin polarization determined from current-induced domain wall motion in a Co/Ni nanowire
K. Ueda; T. Koyama; R. Hiramatsu; D. Chiba; S. Fukami; H. Tanigawa; T. Suzuki; N. Ohshima; N. Ishiwata; Y. Nakatani; K. Kobayashi; T. Ono
APPLIED PHYSICS LETTERS, 100, 20, 202407, May 2012, Peer-reviwed
Scientific journal, English - Switching of a particle in inhomogeneous applied field
Y. Uesaka; H. Endo; Y. Suzuki; Y. Nakatani; N. Hayashi; H. Fukushima
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 324, 7, 1272-1276, Apr. 2012, Peer-reviwed
Scientific journal, English - Domain wall dynamics driven by spin transfer torque and the spin-orbit field
Masamitsu Hayashi; Yoshinobu Nakatani; Shunsuke Fukami; Michihiko Yamanouchi; Seiji Mitani; Hideo Ohno
JOURNAL OF PHYSICS-CONDENSED MATTER, 24, 2, 24221-024221, Jan. 2012, Peer-reviwed, True
Scientific journal, English - Electric field-induced magnetization reversal in a perpendicular-anisotropy CoFeB-MgO magnetic tunnel junction
S. Kanai; M. Yamanouchi; S. Ikeda; Y. Nakatani; F. Matsukura; H. Ohno
APL, AIP Publishing, 101, 12, 122403, 2012, Peer-reviwed, The electric field-induced ∼180° magnetization reversal is realized for a sputtered CoFeB/MgO-based magnetic tunnel junction with perpendicular magnetic easy axis in a static external magnetic field. Application of bias voltage with nanoseconds duration results in a temporal change of magnetic easy axis in the free layer CoFeB to in-plane, which induces precessional motion of magnetization in the free layer. The magnetization reversal takes place when the bias voltage pulse duration is adjusted to a half period of the precession. We show that the back and forth magnetization reversal can be observed by using successive application of half-period voltage pulses.
Scientific journal - Stability of Vortex Structure on Core Switching
T. Sato; Y. Nakatani
J. Magn. Soc. Jpn., The Magnetics Society of Japan, 36, 3, 173-178-178, 2012, Peer-reviwed, The stability of the vortex structure on vortex core switching was investigated by using micromagnetic simulation. The method by the vortex core switching simulation by AC spin current is used to investigate this. Furthermore, the adequacy of the result was investigated by the evaluation of the magnetic energy. The switching simulation revealed that the vortex core did not switch around the transition dimension of magnetic disks between single-domain structure and the vortex structure in a remanent state, and the disk diameter needed to be increased to about 20 to 80 nm for stable vortex core switching compared with the stability limit in the remanent state. Furthermore, the results we obtained from our evaluation of magnetic energy agreed with the results obtained by simulating vortex core switching. Therefore, the result of the core switching simulation is also assured by the evaluation of magnetic energy.
Japanese - All-electrical operation of magnetic vortex core memory cell
K. Nakano; D. Chiba; N. Ohshima; S. Kasai; T. Sato; Y. Nakatani; K. Sekiguchi; K. Kobayashi; T. Ono
APPLIED PHYSICS LETTERS, 99, 26, 262505, Dec. 2011, Peer-reviwed
Scientific journal, English - Influence of Instabilities on High-Field Magnetic Domain Wall Velocity in (Co/Ni) Nanostrips
Keisuke Yamada; Jean-Pierre Jamet; Yoshinobu Nakatani; Alexandra Mougin; Andre Thiaville; Teruo Ono; Jacques Ferre
APPLIED PHYSICS EXPRESS, 4, 11, 113001, Nov. 2011, Peer-reviwed
Scientific journal, English - Spin-RAM for Normally-Off Computer
K. Ando; K. Yakushiji; H. Kubota; A. Fukushima; S. Yuasa; T. Kai; T. Kishi; N. Shimomura; H. Aikawa; M. Yoshikawa; T. Nagase; K. Nishiyama; E. Kitagawa; T. Daibou; M. Amano; S. Takahashi; M. Nakayama; S. Ikegawa; M. Nagamine; J. Ozeki; D. Watanabe; H. Yoda; T. Nozaki; Y. Suzuki; M. Oogane; S. Mizukami; Y. Ando; T. Miyazaki; Y. Nakatani
2011 11th Annual Non-Volatile Memory Technology Symposium Proceeding, IEEE, Nov. 2011, Peer-reviwed
International conference proceedings - Wire Width Dependence of Threshold Current Density for Domain Wall Motion in Co/Ni Nanowires
Tomohiro Koyama; Daichi Chiba; Kohei Ueda; Hironobu Tanigawa; Shunsuke Fukami; Tetsuhiro Suzuki; Norikazu Ohshima; Nobuyuki Ishiwata; Yoshinobu Nakatani; Teruo Ono
IEEE TRANSACTIONS ON MAGNETICS, 47, 10, 3089-3091, Oct. 2011, Peer-reviwed
Scientific journal, English - Effect of the Oersted field on a vortex core switching by pulse spin current
Yoshinobu Nakatani; Teruo Ono
APPLIED PHYSICS LETTERS, 99, 12, 122509, Sep. 2011, Peer-reviwed
Scientific journal, English - Electric spectroscopy of vortex states and dynamics in magnetic disks
Minori Goto; Hiroshi Hata; Akinobu Yamaguchi; Yoshinobu Nakatani; Takehiro Yamaoka; Yukio Nozaki; Hideki Miyajima
PHYSICAL REVIEW B, 84, 6, 64406, Aug. 2011, Peer-reviwed
Scientific journal, English - Electrical Investigation of Notch Width Dependence of Domain Wall Structure in Co/Ni Nanowires
Kouta Kondou; Ryo Hiramatsu; Tomohiro Koyama; Yoshinobu Nakatani; Daichi Chiba; Shunsuke Fukami; Nobuyuki Ishiwata; Teruo Ono
JAPANESE JOURNAL OF APPLIED PHYSICS, 50, 7, 73002, Jul. 2011, Peer-reviwed
Scientific journal, English - Current-Induced Magnetic Domain Wall Motion in Co/Ni Nanowire at Low Temperature
Kohei Ueda; Tomohiro Koyama; Daichi Chiba; Kazutoshi Shimamura; Hironobu Tanigawa; Shunsuke Fukami; Tetsuhiro Suzuki; Norikazu Ohshima; Nobuyuki Ishiwata; Yoshinobu Nakatani; Teruo Ono
APPLIED PHYSICS EXPRESS, 4, 6, 63003, Jun. 2011, Peer-reviwed
Scientific journal, English - Magnetic field insensitivity of magnetic domain wall velocity induced by electrical current in Co/Ni nanowire
T. Koyama; D. Chiba; K. Ueda; H. Tanigawa; S. Fukami; T. Suzuki; N. Ohshima; N. Ishiwata; Y. Nakatani; T. Ono
APPLIED PHYSICS LETTERS, 98, 19, 192509, May 2011, Peer-reviwed
Scientific journal, English - Electrical detection of vortex states in a ferromagnetic disk using the rectifying effect
M. Goto; H. Hata; Yamaguchi; Y. Nakatani; T. Yamaoka; Y. Nozaki
Journal of Applied Physics, The American Institute of Physics, 109, 7, 07D306 (3 pages), 18 Mar. 2011, Peer-reviwed
Scientific journal, English - Observation of the intrinsic pinning of a magnetic domain wall in a ferromagnetic nanowire
T. Koyama; D. Chiba; K. Ueda; K. Kondou; H. Tanigawa; S. Fukami; T. Suzuki; N. Ohshima; N. Ishiwata; Y. Nakatani; K. Kobayashi; T. Ono
NATURE MATERIALS, 10, 3, 194-197, Mar. 2011, Peer-reviwed
Scientific journal, English - Current-induced domain wall motion in perpendicularly magnetized CoFeB nanowire
S. Fukami; T. Suzuki; Y. Nakatani; N. Ishiwata; M. Yamanouchi; S. Ikeda; N. Kasai; H. Ohno
APPLIED PHYSICS LETTERS, 98, 8, 82504, Feb. 2011, Peer-reviwed
Scientific journal, English - Fast Micromagnetic Simulation of Vortex Core Motion by GPU
T. Sato; Y. Nakatani
J. Magn. Soc. Jpn,, The Magnetics Society of Japan, 35, 3, 163-170-170, 2011, Peer-reviwed, Micromagnetic simulation has been used to calculate magnetization distribution and dynamics in nanoscale magnetic materials. A method reducing the calculation time is needed because it requires prolonged periods for calculation. We propose a method of calculation to reduce the calculation time with a graphics processing unit (GPU). The speed with the proposed method is fifteen times faster than that with the conventional one with a CPU at maximum. Because a GPU has very fast single precision calculation units and relatively slow double precision calculation units, it is necessary to use single precision units for fast calculation with a GPU. The difference between the results of one calculation with single and double precision units is very small. However, this difference accumulates in simulations. There is a possibility the results may change due to this difference. This effect is investigated with static and dynamic simulations with a vortex structure in a nanodot. The relative differences in static and dynamic calculations are 10-6 and 0.04, respectively. These differences are sufficiently small for practical simulations. Therefore, a method with a GPU is useful to obtain micromagnetic simulations of vortex core motion.
English - Dependence of prefactor on the angle between an applied field and the easy axis for single-domain particles
Hiroshi Fukushima; Yasutaro Uesaka; Yoshinobu Nakatani; Nobuo Hayashi
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 323, 2, 195-197, Jan. 2011, Peer-reviwed
Scientific journal, English - Detection of vortex-core dynamics using current-induced self-bistable rectifying effect
M. Goto; H. Hata; A. Yamaguchi; H. Miyajima; Y. Nakatani; T. Yamaoka; Y. Nozaki
Journal of Physics, The Institute of Physics, 266, 1, 012080 (5 pages), Jan. 2011, Peer-reviwed
Scientific journal, English - Current-induced switching of magnetic vortex core in ferromagnetic elliptical disks
Keisuke Yamada; Shinya Kasai; Yoshinobu Nakatani; Kensuke Kobayashi; Teruo Ono
APPLIED PHYSICS LETTERS, 96, 19, 192508, May 2010, Peer-reviwed
Scientific journal, English - Simulation of magnetization switching by electric-field manipulation of magnetic anisotropy
D. Chiba; Y. Nakatani; F. Matsukura; H. Ohno
APPLIED PHYSICS LETTERS, 96, 19, 192506, May 2010, Peer-reviwed
Scientific journal, English - High efficient spin transfer torque writing on perpendicular magnetic tunnel junctions for high density MRAMs
Tatsuya Kishi; Toshihiko Nagase; Masatoshi Yoshikawa; Katsuya Nishiyama; Eiji Kitagawa; Tadaomi Daibou; Minoru Amano; Naoharu Shimomura; Shigeki Takahashi; Tadashi Kai; Masahiko Nakayama; Hisanori Aikawa; Sumio Ikegawa; Makoto Nagamine; Junichi Ozeki; Shigemi Mizukami; Mikihiko Oogane; Yasuo Ando; Shinji Yuasa; Kei Yakushiji; Hitoshi Kubota; Yoshishige Suzuki; Yoshinobu Nakatani; Terunobu Miyazaki; Koji Ando
Curr. Appl. Phys., 10, 1, e87-89, Apr. 2010, Peer-reviwed
Scientific journal, English - Control of Multiple Magnetic Domain Walls by Current in a Co/Ni Nano-Wire
Daichi Chiba; Gen Yamada; Tomohiro Koyama; Kohei Ueda; Hironobu Tanigawa; Shunsuke Fukami; Tetsuhiro Suzuki; Norikazu Ohshima; Nobuyuki Ishiwata; Yoshinobu Nakatani; Teruo Ono
APPLIED PHYSICS EXPRESS, 3, 7, 73004, 2010, Peer-reviwed
Scientific journal, English - Relation between critical current of domain wall motion and wire dimension in perpendicularly magnetized Co/Ni nanowires
S. Fukami; Y. Nakatani; T. Suzuki; K. Nagahara; N. Ohshima; N. Ishiwata
APPLIED PHYSICS LETTERS, 95, 23, 232504, Dec. 2009, Peer-reviwed
Scientific journal, English - Domain Wall Motion Induced by Electric Current in a Perpendicularly Magnetized Co/Ni Nano-Wire
Hironobu Tanigawa; Tomohiro Koyama; Gen Yamada; Daichi Chiba; Shinya Kasai; Shunsuke Fukami; Tetsuhiro Suzuki; Norikazu Ohshima; Nobuyuki Ishiwata; Yoshinobu Nakatani; Teruo Ono
APPLIED PHYSICS EXPRESS, 2, 5, 53002, May 2009, Peer-reviwed
Scientific journal, English - Switching field and mechanism of cubic and flat square particles
Y. Uesaka; H. Endo; Y. Nakatani; N. Hayashi; H. Fukushima
JOURNAL OF APPLIED PHYSICS, 105, 7, 07C126, Apr. 2009, Peer-reviwed
Scientific journal, English - Magnetic field dependence of rectification radio frequency current flowing through a single layered ferromagnetic wire
A. Yamaguchi; K. Motoi; H. Miyajima; Y. Nakatani
JOURNAL OF APPLIED PHYSICS, 105, 7, 07D301, Apr. 2009, Peer-reviwed
Scientific journal, English - Micromagnetics of Domain-Wall Dynamics in Soft Nanostrips
André Thiaville; Yoshinobu Nakatani
Nanomagnetism and Spintronics, Elsevier, 231-276, 2009, Peer-reviwed
In book, English - Probing the Spin Polarization of Current by Soft X-Ray Imaging of Current-Induced Magnetic Vortex Dynamics
Shinya Kasai; Peter Fischer; Mi-Young Im; Keisuke Yamada; Yoshinobu Nakatani; Kensuke Kobayashi; Hiroshi Kohno; Teruo Ono
PHYSICAL REVIEW LETTERS, 101, 23, 237203-237203, Dec. 2008, Peer-reviwed, True
Scientific journal, English - Dynamical Pinning of a Domain Wall in a Magnetic Nanowire Induced by Walker Breakdown
Hironobu Tanigawa; Tomohiro Koyama; Maciej Bartkowiak; Shinya Kasai; Kensuke Kobayashi; Teruo Ono; Yoshinobu Nakatani
PHYSICAL REVIEW LETTERS, 101, 20, 207203-207203, Nov. 2008, Peer-reviwed, True
Scientific journal, English - Electrical rectification effect in single domain magnetic microstrips: A micromagnetics-based analysis
Andre Thiaville; Yoshinobu Nakatani
JOURNAL OF APPLIED PHYSICS, 104, 9, 93701, Nov. 2008, Peer-reviwed
Scientific journal, English - Switching magnetic vortex core by a single nanosecond current pulse
Keisuke Yamada; Shinya Kasai; Yoshinobu Nakatani; Kensuke Kobayashi; Teruo Ono
APPLIED PHYSICS LETTERS, 93, 15, 152502, Oct. 2008, Peer-reviwed
Scientific journal, English - Control of Domain Wall Position by Electrical Current in Structured Co/Ni Wire with Perpendicular Magnetic Anisotropy
Tomohiro Koyama; Gen Yamada; Hironobu Tanigawa; Shinya Kasai; Norikazu Ohshima; Shunsuke Fukami; Nobuyuki Ishiwata; Yoshinobu Nakatani; Teruo Ono
APPLIED PHYSICS EXPRESS, 1, 10, 101303, Oct. 2008, Peer-reviwed
Scientific journal, English - Magnetization vector manipulation by electric fields
D. Chiba; M. Sawicki; Y. Nishitani; Y. Nakatani; F. Matsukura; H. Ohno
NATURE, 455, 7212, 515-518, Sep. 2008, Peer-reviwed
Scientific journal, English - Long-range vortex domain wall displacement induced by an alternating current: Micromagnetic simulations
Peter Warnicke; Yoshinobu Nakatani; Shinya Kasai; Teruo Ono
PHYSICAL REVIEW B, 78, 1, 12413, Jul. 2008, Peer-reviwed
Scientific journal, English - Single-shot measurements of spin-transfer switching in CoFeB/MgO/CoFeB magnetic tunnel junctions
Hiroyuki Tomita; Katuaki Konishi; Takayuki Nozaki; Hitoshi Kubota; Akio Fukushima; Kay Yakushiji; Shinji Yuasa; Yoshinobu Nakatani; Teruya Shinjo; Masashi Shiraishi; Yoshishige Suzuki
APPLIED PHYSICS EXPRESS, 1, 6, 61303, Jun. 2008, Peer-reviwed
Scientific journal, English - Single shot detection of the magnetic domain wall motion by using tunnel magnetoresistance effect
Kouta Kondou; Norikazu Ohshima; Shinya Kasai; Yoshinobu Nakatani; Teruo Ono
APPLIED PHYSICS EXPRESS, 1, 6, 61302, Jun. 2008, Peer-reviwed
Scientific journal, English - Magnetic domain wall oscillator
Teruo Ono; Yoshinobu Nakatani
APPLIED PHYSICS EXPRESS, 1, 6, 61301, Jun. 2008, Peer-reviwed
Scientific journal, English - Development of High-speed Differential-Susceptibility Measuring Equipment
KAJI T.; ENDO H.; UESAKA Y.; NAKATANI Y.
Transactions of the Magnetics Society of Japan, The Magnetics Society of Japan (MSJ), 32, 3, 244-249, 01 Apr. 2008, We developed high-speed differential-susceptibility measuring equipment to examine thermal fluctuations in magnetic materials. In this study, we measured the dependence of the differential-susceptibility of a magnetic tape on a magnetic field by using the equipment. When the sweep speed of the magnetic field changed from high to low in the order of ms, the magnetic field that gave the maximum differential susceptibility shifted from a high to a low magnetic field due to thermal fluctuations. However, when the sweep speed of the magnetic field changed from high to low in the order of μs, the shift in magnetic field was not clearly detected. The time when the magnetization in the easy direction changed from the residual to the zero state obtained from a linear field, and the time obtained from the constant field, which is the same as the coercivity of the linear field, were calculated using micromagnetic simulations. From the ratio of the two times and from an experimental time when the applied field reached coercivity, a time that could be applied to Sharrock's equation was obtained. In order to fit the experimental results to Sharrock's equation, Ku must be much smaller than the experimental value and H0 must be much smaller than Hk (H0/Hk=0.38). Here, Ku, Hk, and H0 are anisotropy constat, anisotropy field, and coercivity at 0K.
Japanese - Nucleation and dynamics of magnetic vortices under spin-polarized current
Yoshinobu Nakatani; Junya Shibata; Gen Tatara; Hiroshi Kohno; Andre Thiaville; Jacques Miltat
PHYSICAL REVIEW B, 77, 1, 14439, Jan. 2008, Peer-reviwed
Scientific journal, English - Transient domain wall displacement under spin-polarized current pulses
A. Thiaville; Y. Nakatani; F. Piechon; J. Miltat; T. Ono
EUROPEAN PHYSICAL JOURNAL B, 60, 1, 15-27, Nov. 2007, Peer-reviwed
Scientific journal, English - Rectification of radio frequency current in ferromagnetic nanowire
A. Yamaguchi; H. Miyajima; T. Ono; Y. Suzuki; S. Yuasa; A. Tulapurkar; Y. Nakatani
APPLIED PHYSICS LETTERS, 90, 18, 182507, Apr. 2007, Peer-reviwed
Scientific journal, English - Electrical switching of the vortex core in a magnetic disk
Keisuke Yamada; Shinya Kasai; Yoshinobu Nakatani; Kensuke Kobayashi; Hiroshi Kohno; Andre Thiaville; Teruo Ono
NATURE MATERIALS, 6, 4, 269-273, Apr. 2007, Peer-reviwed, True
Scientific journal, English - Magnetic vortex dynamics induced by spin-transfer torque
J. Shibata; Y. Nakatani; G. Tatara; H. Kohno; Y. Otani
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 310, 2, 2041-2042, Mar. 2007, Peer-reviwed
Scientific journal, English - Magnetization reversal in a ferromagnetic circular dot under current induced resonant excitation
Kasai S; Nakatani Y; Kobayashi K; Kohno H; Ono T
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 310, 2, 2351-2352, Mar. 2007, Peer-reviwed - Switching times of a single-domain particle in a field inclined off the easy axis
Hiroshi Fukushima; Yasutaro Uesaka; Yoshinobu Nakatani; Nobuo Hayashi
JOURNAL OF APPLIED PHYSICS, 101, 1, 13901, Jan. 2007, Peer-reviwed
Scientific journal, English - Formation of magnetic clusters in perpendicular thin films
H. Endo; Y. Uesaka; Y. Nakatani; N. Hayashi; H. Fukushima
IEEE TRANSACTIONS ON MAGNETICS, 42, 10, 2969-2971, Oct. 2006, Peer-reviwed
Scientific journal, English - Current-driven resonant excitation of magnetic vortices
Shinya Kasai; Yoshinobu Nakatani; Kensuke Kobayashi; Hiroshi Kohno; Teruo Ono
PHYSICAL REVIEW LETTERS, 97, 10, 107204-107204, Sep. 2006, Peer-reviwed, True
Scientific journal, English - Switching time of single magnetic particle and maximum recording frequency of perpendicular magnetic recording
Y Uesaka; H Endo; Y Nakatani; N Hayashi; H Fukushima
IEEE TRANSACTIONS ON MAGNETICS, 42, 7, 1892-1895, Jul. 2006, Peer-reviwed
Scientific journal, English - Threshold current of domain wall motion under extrinsic pinning, beta-term and non-adiabaticity
Gen Tatara; Toshihiko Takayama; Hiroshi Kohno; Junya Shibata; Yoshinobu Nakatani; Hidetoshi Fukuyama
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, 75, 6, 64708, Jun. 2006, Peer-reviwed
Scientific journal, English - Influence of in-plane field on the thermal stability of perpendicular media
Y Uesaka; H Endo; N Kodama; Y Nakatani; N Hayashi; H Fukushima
JOURNAL OF APPLIED PHYSICS, 99, 8, Apr. 2006, Peer-reviwed
Scientific journal, English - Current-induced magnetic vortex motion by spin-transfer torque
J Shibata; Y Nakatani; G Tatara; H Kohno; Y Otani
PHYSICAL REVIEW B, 73, 2, 020403(R), Jan. 2006, Peer-reviwed
Scientific journal, English - Magnetic cluster formation in perpendicular thin films
H. Endo; Y. Uesaka; Y. Nakatani; N. Hayashi; H. Fukushima
INTERMAG 2006 - IEEE International Magnetics Conference, 944, 2006, Peer-reviwed
International conference proceedings, English - Dispersion effect of size, exchange and anisotropy of perpendicular media on read/write properties
Y. Nakatani; Y. Uesaka
INTERMAG 2006 - IEEE International Magnetics Conference, 698, 2006, Peer-reviwed
International conference proceedings, English - Effect of grain size on cluster size
H Endo; Y Uesaka; Y Nakatani; N Hayashi; H Fukushima
JOURNAL OF APPLIED PHYSICS, 97, 10, pp. 10E312, May 2005, Peer-reviwed
Scientific journal, English - Head-to-head domain walls in soft nano-strips: a refined phase diagram
Y Nakatani; A Thiaville; J Miltat
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 290, 750-753, Apr. 2005, Peer-reviwed
Scientific journal, English - Magnetization reversal below the Stoner-Wohlfarth field
H Fukushima; Y Uesaka; Y Nakatani; N Hayashi
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 290, 526-529, Apr. 2005, Peer-reviwed
Scientific journal, English - Micromagnetic understanding of current-driven domain wall motion in patterned nanowires
A Thiaville; Y Nakatani; J Miltat; Y Suzuki
EUROPHYSICS LETTERS, 69, 6, 990-996, Mar. 2005, Peer-reviwed
Scientific journal, English - Effect of quartic anisotropy term on read/write properties of perpendicular recording media
Y. Nakatani; N. Hayashi; Y. Uesaka; H. Fukushima
INTERMAG ASIA 2005: Digests of the IEEE International Magnetics Conference, IEEE Computer Society, 678, 2005
International conference proceedings, English - 電流による磁壁駆動 (Review)
多々良源; 河野浩; 柴田絢也; 仲谷栄伸; 山口明啓; 小野輝男
応用物理 ,74巻、12号 ,1598, 2005
Scientific journal, Japanese - Domain wall motion by spin-polarized current: a micromagnetic study
A Thiaville; Y Nakatani; J Miltat; N Vernier
JOURNAL OF APPLIED PHYSICS, 95, 11, 7049-7051, Jun. 2004, Peer-reviwed
Scientific journal, English - Effects of damping constant and gyromagnetic term on switching time of single-domain particle
H Fukushima; Y Uesaka; Y Nakatani; N Hayashi
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 272, 745-746, May 2004, Peer-reviwed
Scientific journal, English - Effects of exchange interaction and grain size distribution on cluster size in perpendicular media
H Endo; Y Uesaka; Y Nakatani; N Hayashi; H Fukushima
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 272, 711-712, May 2004, Peer-reviwed
Scientific journal, English - Measurement of Easy Axis Distribution
SANGUU T.; ENDO H.; UESAKA Y.; NAKATANI Y.; HAYASHI N.; FUKUSHIMA H.
Journal of the Magnetics Society of Japan, The Magnetics Society of Japan, 28, 3, 271-274, 01 Mar. 2004, We used computer simulation to examine an measuring method for easy axis distribution of a recording medium. Remanent magnetization Mr with the field applied in-plane showed that in-plane Mr increases with saturation magnetization Ms when the easy axis distribution is not random in plane, though Mr scarcely changes with Ms when the easy axis distribution is random in plane. We found that easy axis distribution perpendicular to the film plane does not affect in-plane Mr with the field applied in plane. We also found that easy axis distribution perpendicular to the film plane can be estimated from distribution of easy axis in plane, tilted direction of easy axis from the film plane, and perpendicular component of Mr with the field applied out of plane. Good agreements were obtained between experimentally derived remanent magnetization of VTR and audio tapes with the field applied out of plane and Mr derived from computer simulation.
Japanese - Influence of gyromagnetic term and temperature on switching time of a single-domain particle
H Fukushima; Y Uesaka; Y Nakatani; N Hayashi
IEEE TRANSACTIONS ON MAGNETICS, 39, 5, 2519-2521, Sep. 2003, Peer-reviwed
Scientific journal, English - Faster magnetic walls in rough wires
Y Nakatani; A Thiaville; J Miltat
NATURE MATERIALS, 2, 8, 521-523, Aug. 2003, Peer-reviwed, True
Scientific journal, English - Computer simulations of magnetization switching of elongated magnetic particles with shape defects
H Endo; Y Uesaka; Y Nakatani; N Hayashi; H Fukushima
JOURNAL OF APPLIED PHYSICS, 93, 12, 9865-9868, Jun. 2003, Peer-reviwed
Scientific journal, English - Effect of anisotropy field of soft magnetic underlayer on read/write properties in perpendicular recording media
Y Nakatani; N Hayashi; Y Uesaka; H Fukushima
JOURNAL OF APPLIED PHYSICS, 93, 10, 7744-7746, May 2003, Peer-reviwed
Scientific journal, English - Remanent head field study of single pole-type head based on micromagnetics
M Mochizuki; C Ishikawa; H Ide; K Nakamoto; Y Nakatani; N Hayashi
JOURNAL OF APPLIED PHYSICS, 93, 10, 6748-6750, May 2003, Peer-reviwed
Scientific journal, English - Accuracy of the backward-difference solution of the Landau-Lifshitz-Gilbert equation
N Hayashi; Y Nakatani; Y Uesaka
JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS, 42, 3, 1250-1257, Mar. 2003, Peer-reviwed
Scientific journal, English - Analysis of MAMMOS Readout from Crescent Domains Using a Blue Laser
IMAI Susumu; NAKATANI Yoshinobu; AWANO Hiroyuki; ISHIZAKI Osamu; OTA Norio
Journal of the Magnetics Society of Japan, The Magnetics Society of Japan (MSJ), 2, 4, 297-299, 01 Oct. 2002, In the ongoing effort to achieve ultra high density Magneto-Optical recording, Laser Pumped Magnetic Field Modulation (LP-MFM) and Magnetic Amplifying Magneto-Optical System (MAMMOS) are considered promising methods. Using LP-MFM, crescent domains are recorded in a recording layer. Micro-magnetic simulations for the MAMMOS readout have already been reported assuming a crescent domain and red laser irradiation. Huth's equation simulations for the MAMMOS readout have also been reported assuming a circular recorded domain and blue laser irradiation. Micro-magnetic simulations for the MAMMOS readout assuming a blue laser irradiation, however, have not so far been reported. This paper presents the analysis of the combination of a 405nm blue laser and the MAMMOS readout from crescent recorded domains using the micro-magnetic simulations. In this work, MAMMOS readout from a crescent recorded domain is shown to be possible even with blue laser irradiation.
English - Dependence of switching time on temperature, applied field, and material parameters
H Fukushima; Y Uesaka; Y Nakatani; N Hayashi
IEEE TRANSACTIONS ON MAGNETICS, 38, 5, 2394-2396, Sep. 2002, Peer-reviwed
Scientific journal, English - Effect of exchange interaction between grains on R/W properties of single-layer perpendicular recording media
Y Uesaka; H Endo; Y Nakatani; N Hayashi; H Fukushima
IEEE TRANSACTIONS ON MAGNETICS, 38, 5, 2033-2035, Sep. 2002, Peer-reviwed
Scientific journal, English - Thermal stability of written bits in double-layered perpendicular recording media
Y Nakatani; N Hayashi; Y Uesaka; H Fukushima
IEEE TRANSACTIONS ON MAGNETICS, 38, 5, 2036-2038, Sep. 2002, Peer-reviwed
Scientific journal, English - Effect of grain size dispersion on read/write properties in antiferromagnetically coupled recording media affected by thermal fluctuation
Y Nakatani; N Hayashi; Y Uesaka; H Fukushima
JOURNAL OF APPLIED PHYSICS, 91, 10, 7691-7693, May 2002, Peer-reviwed
Scientific journal, English - Numerical solutions of the Fokker-Planck equation by the finite difference method for the thermally assisted reversal of the magnetization in a single-domain particle
H Fukushima; Y Uesaka; Y Nakatani; N Hayashi
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 242, 1002-1004, Apr. 2002, Peer-reviwed
Scientific journal, English - Thermal stability of written bits in AFC recording media
Y Nakatani; N Hayashi; Y Uesaka; H Fukushima
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 242, 409-412, Apr. 2002, Peer-reviwed
Scientific journal, English - Effect of material parameters of underlayer on read/write properties of AFC recording media
Y Nakatani; N Hayashi; Y Uesaka; H Fukushima
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 242, 405-408, Apr. 2002, Peer-reviwed
Scientific journal, English - Numerical simulation of switching time of magnetic particle
Y Uesaka; H Endo; T Takahashi; Y Nakatani; N Hayashi; H Fukushima
PHYSICA STATUS SOLIDI A-APPLIED RESEARCH, 189, 3, 1023-1027, Feb. 2002, Peer-reviwed
Scientific journal, English - Dependence of switching time on temperature
H. Fukushima; Y. Uesaka; Y. Nakatani; N. Hayashi
INTERMAG Europe 2002 - IEEE International Magnetics Conference, Institute of Electrical and Electronics Engineers Inc., 2002, Peer-reviwed
International conference proceedings, English - Micro magnetic mechanism and comparison of domain expansion MO schemes toward 100 Gbit/in2
H. Awano; Y. Nakatani; S. Imai; M. Tani; M. Sekine; N. Ota
2002 International Symposium on Optical Memory and Optical Data Storage Topical Meeting, ISOM/ODS 2002 - Joint International Symposium on Optical Memory and Optical Data Storage 2002, Technical Digest, Institute of Electrical and Electronics Engineers Inc., 39-41, 2002, Peer-reviwed
International conference proceedings, English - Read/write properties of oriented longitudinal recording media
Y Uesaka; Y Nakatani; N Hayashi; H Fukushima
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 235, 1-3, 445-449, Oct. 2001, Peer-reviwed
Scientific journal, English - Magnetization reversal and electric transport in ferromagnetic nanowires
T Ono; Y Ooka; S Kasai; H Miyajima; Y Nakatani; N Hayashi; K Shigeto; K Mibu; T Shinjo
MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY, 84, 1-2, 126-132, Jul. 2001, Peer-reviwed
Scientific journal, English - Computer simulation of domain wall motion in a magnetic strip line with submicron width
Y Nakatani; N Hayashi; T Ono; H Miyajima
IEEE TRANSACTIONS ON MAGNETICS, 37, 4, 2129-2131, Jul. 2001, Peer-reviwed
Scientific journal, English - Time dependence of readout signal and media noise
Y Nakatani; N Hayashi; Y Uesaka; H Fukushima
IEEE TRANSACTIONS ON MAGNETICS, 37, 4, 1544-1546, Jul. 2001, Peer-reviwed
Scientific journal, English - Thermal stability in longitudinal thin film media
F. Akagi; M. Igarashi; K. Yoshida; Y. Nakatani; N. Hayashi
IEEE Transactions on Magnetics, 37, 4 I, 1534-1536, Jul. 2001, Peer-reviwed
International conference proceedings, English - Micromagnetic simulation of wall motion for MAMMOS and DWDD
Y. Nakatani; N. Hayashi
J. Magn. Soc. Japan, The Magnetics Society of Japan, 25, 3, pp. 252-257-257, 2001, Peer-reviwed, The process of domain transcription and wall motion in magneto-optical recording media for MAMMOS and DWDD is investigated by micromagnetic computer simulation. The result of calculation agrees with experiment semiquantitatively, which shows the effectiveness of the micromagnetic simulation in the development of these devices.
English - Effect of thermal fluctuation on reversal field of magnetic fine particle with surface anisotropy
Y Nakatani; N Hayashi; Y Uesaka; H Fukushima; O Kitakami; Y Shimada
IEEE TRANSACTIONS ON MAGNETICS, 36, 5, 3205-3207, Sep. 2000, Peer-reviwed
Scientific journal, English - Effect of angle dependent attempt frequency on Arrhenius-Neel thermal decay in thin film media
M Igarashi; F Akagi; K Yoshida; Y Nakatani
IEEE TRANSACTIONS ON MAGNETICS, 36, 5, 2459-2461, Sep. 2000, Peer-reviwed
Scientific journal, English - Micromagnetic Simulation of Wall Motion in Domain Wall Displacement Detection.
Kamata K.; Nakatani Y.; Shiratori T.; Kobayashi T.
Journal of the Magnetics Society of Japan, The Magnetics Society of Japan, 24, 9, pp. 1267-1270-1270, 2000, Peer-reviwed, A computer simulation of wall motion in domain wall displacement detection (DWDD) was performed using a micromagnetic model. The mechanism of the wall motion in the displacement layer and the effect of the track width and the defect of the track edge on the wall motion were investigated.
Japanese - Grain Size Dispersion Model of Magnetic Recording Media.
Oshima T.; Nakatani Y.
Journal of the Magnetics Society of Japan, The Magnetics Society of Japan, 24, 7, pp. 1157-1161-1161, 2000, Peer-reviwed, A grain size dispersion model for calculating the properties of magnetic recording media is proposed. The magnetic property and the read/write properties of several media were calculated by using this model and three previously proposed models to investigate the effect of the calculation model on the results. Simulation results show the validity of the proposed method.
Japanese - Effect of thermal fluctuation of reversal field of magnetic fine particle with surface anisotropy
Y. Nakatani; N. Hayashi; Y. Uesaka; H. Fukushima
Digests of the Intermag Conference, IEEE, 2000
International conference proceedings, English - Effect of inter-granular exchange coupling on read/write properties in thin film recording media affected by thermal fluctuation
Y Nakatani; N Hayashi; Y Uesaka; H Fukushima
JOURNAL OF APPLIED PHYSICS, 85, 8, 4726-4728, Apr. 1999, Peer-reviwed
Scientific journal, English - Computer simulation of SNR in longitudinal and perpendicular recording
Y Uesaka; Y Nakatani; N Hayashi; H Fukushima
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 193, 1-3, 399-405, Mar. 1999, Peer-reviwed
Scientific journal, English - Physics of Domain Wall in Readout Layer of Magnetic Amplifying Magneto-Optical System
N. Hayashi; Y. Nakatani; H. Awano; N. Ohta
J. Magn. Soc. Jpn., The Magnetics Society of Japan, 23, 1, pp.151-156-156, 1999, Peer-reviwed, The results of two-dimensional dynamic calculations performed to simulate the domain transcription process in the readout layer of a magnetostatically coupled dual-layer magneto-optical recording medium and those of one-dimensional calculations made to clarify the nature of the domain wall in the readout layer are given. Detailed time-dependent magnetization behaviors in the readout layer are obtained in the former calculation showing the effect of various parameters such as the atmosphere temperature, stray fields from the recording layer and external fields, on domain transcription. The coercivity of the readout layer is realized by introducing dispersion into the magnitude of the anisotropy constant among computing cells, and the Landau-Lifshitz-Gilbert equation is solved numerically. The magnetization structures in a straight-line wall both in equilibrium and in motion are calculated in the latter calculation.
English - Accuracy of 45° tbrque method for obtaining anisotropy constant of 2D random films
Yasutaro Uesaka; Yoshinobu Nakatani; Hiroshi Fukushima; Nobuyuki Inaba
IEEE Transactions on Magnetics, 35, 5, 2673-2675, 1999, Peer-reviwed
Scientific journal, English - Influence of Damping Constant .ALPHA. on Recording Characteristics at High Frequencies.
Akagi F.; Igarashi M.; Yoshida K.; Nakatani Y.; Hayashi N.
Journal of the Magnetics Society of Japan, The Magnetics Society of Japan, 23, 4, pp. 1005-1008-1008, 1999, Peer-reviwed, The influence of the damping constant α on recording characteristics at high frequencies was simulated by using the Langevin equation, with the condition that the head field rise time is constant. In the frequency range up to 190 MHz the signal outputs for α = 1 and α = 0.05 are same. On the other hand, in the higher- frequency range over 190 MHz, where the head field decreases before it reaches the maximum value, the signal outputs for α = 0.05 are larger than those for α =1.0. This is because the critical switching field depends on the damping constant α and it decreases with a lower value of α.
Japanese - 45° torque method for obtaining anisotropy constant
Y. Uesaka; Y. Nakatani; N. Hayashi; H. Fukushima; N. Inaba
Digests of the Intermag Conference, IEEE, 1999
International conference proceedings, English - Computer simulation of thermal fluctuation of a fine magnetic particle
Y. Nakatani; N. Hayashi; Y. Uesaka; H. Fukushima
Digests of the Intermag Conference, IEEE, 1999
International conference proceedings, English - Computation of density of longitudinal recording
Y. Uesaka; Y. Nakatani; N. Hayashi; H. Fukushima
Digests of the Intermag Conference, IEEE, 1999
International conference proceedings, English - Effect of grain-size dispersion on read/write properties in thin film recording media affected by thermal fluctuation
Y Nakatani; N Hayashi; Y Uesaka; H Fukushima
IEEE TRANSACTIONS ON MAGNETICS, 34, 4, 1618-1620, Jul. 1998, Peer-reviwed
Scientific journal, English - Influence of Permanent Magnet Film Structures on the Read Characteristics of MR Heads
ISHIKAWA C.; TOTSUKA K.; IGARASHI M.; SUZUKI Y.; NAKATANI Y.; HAYASHI N.
Journal of the Magnetics Society of Japan, The Magnetics Society of Japan, 22, 4, 253-256, 15 Apr. 1998, The output fluctuations of magnetoresistive (MR) heads with abutted permanent magnets were analyzed by micro-magnetic simulation. The longitudinal bias field was calculated from the magnetization configuration of the permanent magnet (PM) film. The output fluctuation of the MR head was simulated by using the longitudinal bias field, which was calculated with various interface structures between the MR and PM films. When the PM film covered the track edge of the MR capping layer, the longitudinal bias field near the track edge was locally reduced. The local reduction of the bias field was caused by an extra field generated by a charge appearing at the edge of the region where the PM film overlaps the capping layer. It is proved that an MR head with a PM film covering the edge of the capping layer shows output fluctuation, whereas the output is stable when the PM film does not cover the capping layer.
Japanese - Volume average demagnetizing tensor of rectangular prisms
H Fukushima; Y Nakatani; N Hayashi
IEEE TRANSACTIONS ON MAGNETICS, 34, 1, 193-198, Jan. 1998, Peer-reviwed
Scientific journal, English - Monte Carlo simulation of thermal fluctuation in magnetization of longitudinal and perpendicular magnetic recording media
Y Uesaka; Y Takahashi; Y Nakatani; N Hayashi; H Fukushima
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 174, 1-2, 203-218, Oct. 1997, Peer-reviwed
Scientific journal, English - Micromagnetic calculation of domain structure in thin magnetic film based on improved LaBonte method
N Hayashi; K Kosavisutte; Y Nakatani
IEEE TRANSACTIONS ON MAGNETICS, 33, 5, 4164-4166, Sep. 1997, Peer-reviwed
Scientific journal, English - Simulation of MR response to transverse magnetic fields
K Fujimoto; K Totsuka; Y Uesaka; Saitoh, I; H Fukui; F Akagi; Yoshihara, I; Y Nakatani; N Hayashi
IEEE TRANSACTIONS ON MAGNETICS, 33, 3, 2386-2391, May 1997, Peer-reviwed
Scientific journal, English - Computer simulation of thermal fluctuation of fine particle magnetization based on Langevin equation
Y Nakatani; Y Uesaka; N Hayashi; H Fukushima
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 168, 3, 347-351, Apr. 1997, Peer-reviwed
Scientific journal, English - Thermal stability of longitudinal and perpendicular recording media obtained by Monte Carlo simulation
Y Uesaka; Y Nakatani; N Hayashi; H Fukushima
JOURNAL OF APPLIED PHYSICS, 81, 8, 4841-4841, Apr. 1997
English - Effect of thermal fluctuation on read/write properties of longitudinal and perpendicular recording media
Y Nakatani; N Hayashi; Y Uesaka; H Fukushima
JOURNAL OF APPLIED PHYSICS, 81, 8, 4842-4842, Apr. 1997
English - Simulation of Thermal Fluctuation in Magnetizatoin of Longitudinal and Prependicular Recording Media with Grain Size Distribution
Y. Uesaka; Y. Nakatani; N. Hayashi; H. Fukushima
J. Mag. Soc. Jpn., 21, pp.277-282-282, 1997, Peer-reviwed - Calculation of demagnetizing field distribution based on fast Fourier transform of convolution
N Hayashi; K Saito; Y Nakatani
JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS, 35, 12A, 6065-6073, Dec. 1996, Peer-reviwed
Scientific journal, English - Parallel Computation of a Demagnetizing Field in a Distributed Environment
Y. Nakatani
J. Mag. Soc. Japan, The Magnetics Society of Japan, 20, 1, pp. 35-40-40, 1996, Peer-reviwed, A parallel computation system for calculating a demagnetizing field in a distributed environment is presented. The system uses a hierarchically organized communication structure to reduce the time needed for communication between workstations. When 139 workstations were used, the total calculation speed was the same as that of a vector-type supercomputer with a computing speed of 1 GFLOPS.
English - Switching of single hexagonal particles with nonuniform magnetic properties
Y Uesaka; Y Nakatani; N Hayashi
JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS, 34, 11, 6056-6062, Nov. 1995, Peer-reviwed
Scientific journal, English - METHOD OF MEASURING ANISOTROPY-FIELD OF A RECORDING MEDIUM INVESTIGATED BY COMPUTER-SIMULATION
Y UESAKA; T YOSHIDA; Y NAKATANI; N HAYASHI
JOURNAL OF APPLIED PHYSICS, 77, 10, 5303-5308, May 1995, Peer-reviwed
Scientific journal, English - COMPUTER-SIMULATION OF MAGNETIZATION REVERSAL OF CUBIC, THIN AND ELONGATED PARTICLES - EFFECT OF METHOD OF CALCULATING DEMAGNETIZING FIELD
Y UESAKA; Y NAKATANI; N HAYASHI
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 145, 1-2, 205-210, Mar. 1995, Peer-reviwed
English - EFFECT OF DAMPING CONSTANT ON SWITCHING OF HEXAGONAL PLATELET PARTICLE
Y NAKATANI; N HAYASHI; Y UESAKA; H FUJIWARA
JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS, 33, 12A, 6546-6548, Dec. 1994, Peer-reviwed
Scientific journal, English - INFLUENCE OF LONGITUDINAL BIAS FIELD ON MAGNETIZATION DISTRIBUTION IN MAGNETORESISTIVE HEAD WITH SHIELD FILMS
C ISHIKAWA; K SUZUKI; K YOSHIDA; Y SUGITA; K SHINAGAWA; Y NAKATANI; N HAYASHI
JOURNAL OF APPLIED PHYSICS, 75, 2, 1036-1040, Jan. 1994, Peer-reviwed
Scientific journal, English - COMPUTER-SIMULATION OF THIN-FILM MEDIA NOISE USING AN AUTOCORRELATION FUNCTION ALONG THE TRACK DIRECTION
K YOSHIDA; M HARA; Y UESAKA; Y NAKATANI; N HAYASHI
JOURNAL OF APPLIED PHYSICS, 75, 2, 1190-1200, Jan. 1994, Peer-reviwed
Scientific journal, English - SIMULATION OF MAGNETIZATION DISTRIBUTION IN MAGNETORESISTIVE FILM UNDER A LONGITUDINAL BIAS FIELD
C ISHIKAWA; K SUZUKI; N KOYAMA; K YOSHIDA; Y SUGITA; K SHINAGAWA; Y NAKATANI; N HAYASHI
JOURNAL OF APPLIED PHYSICS, 74, 9, 5666-5671, Nov. 1993, Peer-reviwed
Scientific journal, English - COMPUTER-SIMULATION OF ANNIHILATION PROCESS OF VERTICAL BLOCH LINE PAIR
Y NAKATANI; N HAYASHI
IEEE TRANSACTIONS ON MAGNETICS, 29, 6, 2587-2589, Nov. 1993, Peer-reviwed
Scientific journal, English - COMPUTATION OF SWITCHING FIELDS OF STACKED MAGNETIC HEXAGONAL PARTICLES WITH DIFFERENT HEIGHTS
Y UESAKA; Y NAKATANI; N HAYASHI
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 124, 3, 341-346, Jun. 1993, Peer-reviwed
Scientific journal, English - COMPUTER-SIMULATIONS OF SWITCHING FIELDS AND MAGNETIZATION REVERSAL MECHANISMS OF INTERACTING CUBIC PARTICLES - CASES WITH FIELDS APPLIED PARALLEL TO THE EASY AXES
Y UESAKA; Y NAKATANI; N HAYASHI
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 123, 1-2, 209-218, May 1993, Peer-reviwed
Scientific journal, English - COMPUTER-SIMULATIONS OF SWITCHING FIELDS AND MAGNETIZATION REVERSAL MECHANISMS OF INTERACTING CUBIC PARTICLES - CASES WITH FIELDS APPLIED PARALLEL TO THE EASY AXES
Y UESAKA; Y NAKATANI; N HAYASHI
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 123, 1-2, 209-218, May 1993, Peer-reviwed
Scientific journal, English - COMPUTER-SIMULATION OF MAGNETIZATION STATES IN A MAGNETIC THIN-FILM CONSISTING OF MAGNETOSTATICALLY COUPLED GRAINS WITH RANDOMLY ORIENTED CUBIC ANISOTROPY
O MURATA; K SAITO; Y NAKATANI; N HAYASHI
JOURNAL OF APPLIED PHYSICS, 73, 10, 6513-6515, May 1993, Peer-reviwed
Scientific journal, English - COMPUTER-SIMULATION OF SWITCHING FIELDS AND MAGNETIZATION STATES OF INTERACTING CUBIC PARTICLES - CASES WITH FIELDS APPLIED PARALLEL TO THE HARD AXES
Y UESAKA; Y NAKATANI; N HAYASHI
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 123, 3, 337-358, May 1993, Peer-reviwed
Scientific journal, English - S/N RATIO OF THIN-FILM MEDIA ESTIMATED BY COMPUTER-SIMULATION
K YOSHIDA; M HARA; Y UESAKA; Y NAKATANI; N HAYASHI
JOURNAL OF APPLIED PHYSICS, 73, 10, 5578-5578, May 1993
English - MICROMAGNETIC COMPUTATION OF DAMPING CONSTANT EFFECT ON SWITCHING MECHANISM OF A HEXAGONAL PLATELET PARTICLE
Y UESAKA; Y NAKATANI; N HAYASHI
JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS, 32, 3A, 1101-1106, Mar. 1993, Peer-reviwed
Scientific journal, English - COMPUTATION OF SWITCHING FIELDS OF STACKED MAGNETIC HEXAGONAL PLATELET PARTICLES
Y UESAKA; Y NAKATANI; N HAYASHI
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS, 114, 1-2, 217-223, Aug. 1992, Peer-reviwed
Scientific journal, English - DYNAMICAL CALCULATION OF MAGNETIZATION REVERSAL IN SMALL PARTICLES
UESAKA Yasutaro; NAKATANI Yoshinobu; HAYASHI Nobuo
ITE Technical Report, The Institute of Image Information and Television Engineers, 16, 44, 43-48, 1992, The Landau- Lifshitz-Gilbert (LLG) equation is solved to investigate the switching fields and magnetization reversal mechanisms of cubic, elongated, or hexagonal platelet particles. Squareness scarcely changes until the particle size exceeds a critical value. Some time interval is necessary for the irreversal transition to occur in each case. The switching fields and the magnetization reversal mechanisms of the particles change with the material parameters (size, exchange stiffness constant, anisotropy constant).
English - 2 INTERACTING CUBIC PARTICLES - EFFECT OF PLACEMENT ON SWITCHING FIELD AND MAGNETIZATION REVERSAL MECHANISM
GWD SPRATT; Y UESAKA; Y NAKATANI; N HAYASHI
IEEE TRANSACTIONS ON MAGNETICS, 27, 6, 4790-4792, Nov. 1991, Peer-reviwed
Scientific journal, English - COMPUTER-SIMULATION OF MAGNETIZATION REVERSAL MECHANISMS OF HEXAGONAL PLATELET PARTICLE - EFFECT OF MATERIAL PARAMETERS
Y NAKATANI; N HAYASHI; Y UESAKA
JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS, 30, 10, 2503-2512, Oct. 1991, Peer-reviwed
Scientific journal, English - MICROMAGNETIC CALCULATION OF APPLIED FIELD-EFFECT ON SWITCHING MECHANISM OF A HEXAGONAL PLATELET PARTICLE
Y UESAKA; Y NAKATANI; N HAYASHI
JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS, 30, 10, 2489-2502, Oct. 1991, Peer-reviwed
Scientific journal, English - ON THE INFLUENCE OF WALL MICRODEFORMATIONS ON BLOCH LINE VISIBILITY IN BUBBLE GARNETS
A THIAVILLE; J BENYOUSSEF; Y NAKATANI; J MILTAT
JOURNAL OF APPLIED PHYSICS, 69, 8, 6090-6095, Apr. 1991, Peer-reviwed
Scientific journal, English - COMPUTER-SIMULATION OF MAGNETIZATION REVERSAL - THE EFFECT OF SHAPE AND UNIAXIAL CRYSTALLINE ANISOTROPY
G SPRATT; Y UESAKA; Y NAKATANI; N HAYASHI
JOURNAL OF APPLIED PHYSICS, 69, 8, 4850-4852, Apr. 1991, Peer-reviwed
Scientific journal, English - COMPUTER-SIMULATION OF MAGNETIZATION REVERSAL IN FINE HEXAGONAL PLATELET PARTICLES WITH DEFECTS
Y UESAKA; Y NAKATANI; N HAYASHI
JOURNAL OF APPLIED PHYSICS, 69, 8, 4847-4849, Apr. 1991, Peer-reviwed
Scientific journal, English - DYNAMIC CALCULATION OF MAGNETIZATION REVERSAL IN ELONGATED PARTICLES
Y UESAKA; Y NAKATANI; N HAYASHI
JOURNAL OF APPLIED PHYSICS, 67, 9, 5146-5148, May 1990, Peer-reviwed
Scientific journal, English - COMPUTER-SIMULATION OF MAGNETIZATION REVERSAL IN FINE HEXAFERRITE PARTICLES
Y NAKATANI; Y UESAKA; N HAYASHI
JOURNAL OF APPLIED PHYSICS, 67, 9, 5143-5145, May 1990, Peer-reviwed
Scientific journal, English - A Note on Deleting the Maximum Element in Nested S-Heap
K. Noshita; Y. Nakatani
Trans. on the IECE, E 73, pp. 1725-1726, 1990, Peer-reviwed - DIRECT SOLUTION OF THE LANDAU-LIFSHITZ-GILBERT EQUATION FOR MICROMAGNETICS
Y NAKATANI; Y UESAKA; N HAYASHI
JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS, 28, 12, 2485-2507, Dec. 1989, Peer-reviwed
Scientific journal, English - DIRECT SOLUTION OF LANDAU-LIFSHITZ-GILBERT EQUATION FOR DOMAIN-WALLS IN THIN PERMALLOY-FILMS
N HAYASHI; T INOUE; Y NAKATANI; H FUKUSHIMA
IEEE TRANSACTIONS ON MAGNETICS, 24, 6, 3111-3113, Nov. 1988, Peer-reviwed
Scientific journal, English - 3-DIMENSION CALCULATION OF VERTICAL BLOCH LINE AND BLOCH POINT
Y NAKATANI; N HAYASHI
IEEE TRANSACTIONS ON MAGNETICS, 24, 6, 3039-3041, Nov. 1988, Peer-reviwed
Scientific journal, English - NUMERICAL-SOLUTION OF LANDAU-LIFSHITZ-GILBERT EQUATION WITH 2 SPACE VARIABLES FOR VERTICAL BLOCH LINES
N HAYASHI; Y NAKATANI; T INOUE
JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS, 27, 3, 366-378, Mar. 1988, Peer-reviwed
Scientific journal, English - COMPUTER-SIMULATION OF TWO-DIMENSIONAL VERTICAL BLOCH LINES BY DIRECT INTEGRATION OF GILBERT EQUATION
Y NAKATANI; N HAYASHI
IEEE TRANSACTIONS ON MAGNETICS, 23, 5, 2179-2181, Sep. 1987, Peer-reviwed
Scientific journal, English - Variational calculus for vertical bloch lines.
Nakatani Y.; Hayashi N.
Journal of the Magnetics Society of Japan, The Magnetics Society of Japan, 11, 2, pp. 133-138-138, 1987, Peer-reviwed, Magnetization distributions around vertical Bloch lines (VBL's) in the wall-center plane are calculated by direct minimization of the energy of the system. A successive approximation method using the Newton's method has been developed to solve the Euler equation numerically. The method has been found very effective to obtain equilibrium configurations in small iteration steps as compared with the dynamic calculation based on the so-called equation of wall motion. The calculation includes two-dimensional VBL's in which variations along the Z-axis are neglected and three-dimensional VBL's in which surface-to-surface magnetization twist is taken into consideration. Effective interaction field between two VBL's is calculated as a function of the VBL separation in both cases. The paper descibes the formulation of the problem, method of numerical calculation, and results.
Japanese - COMPUTER-SIMULATION OF MAGNETIC DOMAIN-WALL MOTION TO DERIVE EFFECTIVE INTERACTION FORCES BETWEEN VERTICAL BLOCH LINES
N HAYASHI; Y NAKATANI
IEEE TRANSACTIONS ON MAGNETICS, 22, 5, 796-798, Sep. 1986, Peer-reviwed
Scientific journal, English - NUMERICAL-CALCULATION OF MAGNETIC-BUBBLE DOMAIN-WALL MOTION BASED ON A LUMPED-CONSTANT MODEL OF VERTICAL BLOCH LINES
N HAYASHI; Y NAKATANI
JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS, 25, 3, 406-418, Mar. 1986, Peer-reviwed
Scientific journal, English - COMPUTER-SIMULATION OF THE MOTION OF MAGNETIC DOMAIN-WALL BASED ON LUMPED-CONSTANT MODEL OF VERTICAL BLOCH LINES
N HAYASHI; Y NAKATANI
IEEE TRANSACTIONS ON MAGNETICS, 21, 5, 1767-1769, 1985, Peer-reviwed
Scientific journal, English - A lumped-constant model of vertical Bloch lines.
Hayashi N.; Nakatani Y.
Journal of the Magnetics Society of Japan, The Magnetics Society of Japan, 9, 2, pp. 181-186-186, 1985, Peer-reviwed, A formulation has been developed in which the magnetization structure along a magnetic domain wall within a vertical Bloch line is regarded as packed into a single point on the wall, concentrated Bloch-line point. Equations of motion have been derived for the concentrated Bloch line from equations of wall motion developed previously for a two-dimensional wall which was regarded as a locus of domain-center points. Programs have been developed to solve the motion of a domain wall which is arbitrary in shape and contains arbitrary number of concentrated Bloch lines. The results of computer simulation made for bubbles and plane-like walls show the validity of the formulation and the numerical method. The new equations of motion for concentrated Bloch line have been found not to be as stiff as the conventional equations of wall motion in the case with Bloch lines. An outline of the formulation and the method of numerical solution are presented together with preliminary results of computer simulation.
Japanese - Lumped Constant and Distributed Models of Vertical Bloch Lines
N. Hayashi; Y. Nakatani
IEEE Translation Journal on Magnetics in Japan, 1, 9, 1148-1150, 1985, Peer-reviwed
Scientific journal, English - Numerical Stability of Lumped Constant Model for VBL Dynamics
N. Hayashi; Y. Nakatani
IEEE Translation Journal on Magnetics in Japan, 1, 9, 1153-1154, 1985, Peer-reviwed
Scientific journal, English - Lumped Constant Model for VBL Pair
N. Hayashi; Y. Nakatani
IEEE Translation Journal on Magnetics in Japan, 1, 9, 1151-1152, 1985, Peer-reviwed
Scientific journal, English - Computer Simulation of the Motion of a Domain Wall Containing Lumped—Constant Bloch Lines
N. Hayashi; Y. Nakatani
IEEE Translation Journal on Magnetics in Japan, 1, 2, 247-248, 1985, Peer-reviwed
Scientific journal, English
MISC
- Information Stability in Heat-Assisted Magnetic Recording
T. Kobayashi; Y. Nakatani; Y. Fujiwara
Dec. 2019, IEICE Technical Report, MRIS2019, 44, 41-46, Japanese, Summary national conference - Computer simulation of domain wall motion induced by a slope electric field.
S. Murayama; K. Yamada; Y. Nakatani
2015, 2015 IEEE MAGNETICS CONFERENCE (INTERMAG), English, Summary international conference, WOS:000381606001466 - 9pBF-5 Switching of a Magnetic Vortex Core in a Pac-man Disk using a Single Current Pulse
Yamada Keisuke; Sato Tomonori; Nakatani Yoshinobu
The Physical Society of Japan (JPS), 22 Aug. 2014, Meeting abstracts of the Physical Society of Japan, 69, 2, 309-309, Japanese, 1342-8349, 110009887305, AA11439205 - 9pBF-7 Domain wall dynamics in the presence of the Dzyaloshinskii-Moriya interaction
Yoshimura Yoko; Kim Kab-Jin; Taniguchi Takuya; Ueda Kohei; Hiramatsu Ryo; Moriyama Takahiro; Tanigawa Hironobu; Suzuki Tetsuhiro; Kariyada Eiji; Nakatani Yoshinobu; Ono Teruo
The Physical Society of Japan (JPS), 22 Aug. 2014, Meeting abstracts of the Physical Society of Japan, 69, 2, 310-310, Japanese, 1342-8349, 110009887307, AA11439205 - 28aAF-3 Observation of metastable bound state between domain walls in an asymmetric Co/Ni nanowire II
Hiramatsu R.; Kim Kab-Jin; Hata H.; Taniguchi T.; Tanigawa H.; Kariyada H.; Suzuki T.; Nakatani Y.; Moriyama T.; Ono T.
The Physical Society of Japan (JPS), 05 Mar. 2014, Meeting abstracts of the Physical Society of Japan, 69, 1, 510-510, Japanese, 1342-8349, 110009835391, AA11439205 - 28aAF-4 Switching of the Magnetic Vortex Core in a Pac-man Disk
Yamada Keisuke; Sato Tomonori; Nakatani Yoshinobu
The Physical Society of Japan (JPS), 05 Mar. 2014, Meeting abstracts of the Physical Society of Japan, 69, 1, 510-510, Japanese, 1342-8349, 110009835392, AA11439205 - Mechanism change of current-induced magnetic domain wall motion in multilayered Co/Ni nanowires
Ueda K.; Kim K-J.; Hiramatsu R.; Moriyama T.; Chiba D.; Tanigawa H.; Kariyada E.; Suzuki T.; Nakatani Y.; Ono T.
The Physical Society of Japan (JPS), 26 Aug. 2013, Meeting abstracts of the Physical Society of Japan, 68, 2, 367-367, Japanese, 1342-8349, 110009756557, AA11439205 - Switching of the Magnetic Vortex Core in Elliptical Disks by Nano-second Field Pulses
Yamada Keisuke; Sato Tomonori; Nakatani Yoshinobu; Kasai Shinya; Chiba Daichi; Kobayashi Kensuke; Thiaville Andre; Ono Teruo
The Physical Society of Japan (JPS), 26 Aug. 2013, Meeting abstracts of the Physical Society of Japan, 68, 2, 424-424, Japanese, 1342-8349, 110009756772, AA11439205 - Influence of spin Hall effect for current-induced domain wall motion in a perpendicularly magnetized Co/Ni nanowire
Yoshimura Y.; Koyama T.; Moriyama T.; Kim Kab-Jin; Chiba D.; Nakatani Y.; Fukami S.; Yamanouchi M.; Ohno H.; Ono T.
The Physical Society of Japan (JPS), 26 Aug. 2013, Meeting abstracts of the Physical Society of Japan, 68, 2, 415-415, Japanese, 1342-8349, 110009756743, AA11439205 - 27pXA-6 Current pulse width dependence of magnetic domain wall motion in the presence of bias magnetic field
Kim Kab-Jin; Chiba D.; Nakatani Y.; Fukami S.; Yamanouchi M.; Ohno H.; Ono T.
The Physical Society of Japan (JPS), 26 Mar. 2013, Meeting abstracts of the Physical Society of Japan, 68, 1, 540-540, English, 1342-8349, 110009644377, AA11439205 - 26aPS-18 Detection of magnetization rotation in domain wall induced by spin transfer torque in Co/Ni nanowire
Kim Kab-Jin
The Physical Society of Japan (JPS), 26 Mar. 2013, Meeting abstracts of the Physical Society of Japan, 68, 1, 502-502, Japanese, 1342-8349, 110009644237, AA11439205 - 26aPS-17 Current-induced domain wall motion in a perpendicularly magnetized Co/Ni nanowire under in-plane magnetic field (III)
Yoshimura Y; Koyama T; Moriyama T; Chiba D; Tanigawa H; Kariyada E; Suzuki T; Nakatani Y; Ono T
The Physical Society of Japan, 2013, Meeting Abstracts of the Physical Society of Japan, 68, 0, 502-502, Japanese, 1342-8349, 110009644236, AA11439205 - 27pXA-5 Temperature Dependence of Current-Induced Magnetic Domain Wall Motion in a Multilayered Co/Ni Nanowire with MgO Cap
上田 浩平; 小野 輝男; 平松 亮; キムカブジン; 森山 貴広; 千葉 大地; 谷川 博信; 苅屋田 英嗣; 鈴木 哲広; 仲谷 栄伸
The Physical Society of Japan, 2013, Meeting Abstracts of the Physical Society of Japan, 68, 0, 539-539, Japanese, 1342-8349, 110009644376, AA11439205 - 27aAA-9 Current-induced domain wall motion in a perpendicularly magnetized Co/Ni nanowire under in-plane magnetic field
Yoshimura Y; Koyama T; Chiba D; Fukami S; Yamanouchi M; Ohno H; Nakatani Y; Ono T
The Physical Society of Japan, 2012, Meeting Abstracts of the Physical Society of Japan, 67, 0, 533-533, Japanese, 1342-8349, 110009566778, AA11439205 - 27aAA-10 High-field motion of magnetic domain wall in (Co/Ni) nanostrips
Yamada K; Jamet Jean-Pierre; Nakatani Y; Ueda K; Mougin Alexandra; Thiaville Andre; Ono T; Ferre Jacques
The Physical Society of Japan, 2012, Meeting Abstracts of the Physical Society of Japan, 67, 0, 533-533, Japanese, 1342-8349, 110009566779, AA11439205 - 20aCC-10 Current-induced domain wall motion in a perpendicularly magnetized Co/Ni nanowire under in-plane magnetic field (II)
Yoshimura Y; Koyama T; Chiba D; Fukami S; Yamanouchi M; Ohno H; Nakatani Y; Ono T
The Physical Society of Japan, 2012, Meeting Abstracts of the Physical Society of Japan, 67, 0, 427-427, Japanese, 1342-8349, 110009600017, AA11439205 - 27aAA-8 Temperature Dependence of Spin Polarization of Current in Co/Ni Nanowire Estimated from Current-Induced Magnetic Domain Wall Motion
Ueda K; Nakatani Y; Ono T; Koyama T; Hiramatsu R; Chiba D; Fukami S; Tanigawa H; Suzuki T; Ohshima N; Ishiwata N
一般社団法人 日本物理学会, 2012, Meeting Abstracts of the Physical Society of Japan, 67, 0, 533-533, Japanese, 1342-8349, 110009566777, AA11439205 - 24aPS-28 Detection of magnetization rotation in domain wall induced by spin transfer torque
Hiramatsu R; Kondou K; Koyama T; Chiba D; Fukami S; Ishiwata N; Nakatani Y; Ono T
The Physical Society of Japan, 2012, Meeting Abstracts of the Physical Society of Japan, 67, 0, 481-481, Japanese, 1342-8349, 110009566582, AA11439205 - 24aPS-29 Additivity of magnetic domain wall velocities induced by current and field
Koyama T; Ueda K; Chiba D; Fukami S; Ishiwata N; Kohno H; Nakatani Y; Kobayashi K; Ono T
The Physical Society of Japan, 2012, Meeting Abstracts of the Physical Society of Japan, 67, 0, 481-481, Japanese, 1342-8349, 110009566583, AA11439205 - 27aAA-3 Manipulation of the vortex core damping motion
Nakano K; Chiba D; Ohshima N; Kasai S; Sato T; Nakatani Y; Sekiguchi K; Kobayashi K; Ono T
The Physical Society of Japan, 2012, Meeting Abstracts of the Physical Society of Japan, 67, 0, 531-531, Japanese, 1342-8349, 110009566772, AA11439205 - 19aCC-12 Detection of magnetization rotation in domain wall induced by spin transfer torque in Co/Ni nanowire III
Hiramatsu R; Koyama T; Chiba D; Fukami S; Ishiwata N; Nakatani Y; Ono T
The Physical Society of Japan, 2012, Meeting Abstracts of the Physical Society of Japan, 67, 0, 414-414, Japanese, 1342-8349, 110009599977, AA11439205 - 25pHF-7 Vortex resonance and rectifying effect
Goto M.; Hata H.; Yamaguchi A.; Nozaki Y.; Nakatani Y.; Yamaoka T.
The Physical Society of Japan (JPS), 03 Mar. 2011, Meeting abstracts of the Physical Society of Japan, 66, 1, 477-477, Japanese, 1342-8349, 110008713948, AA11439205 - 25pHF-8 Real-time detection of the vortex core resonance motion.
Nakano K; Chiba D; Ohshima N; Kasai S; Sato T; Nakatani Y; Sekiguchi K; Kobayashi K; Ono T
The Physical Society of Japan, 2011, Meeting Abstracts of the Physical Society of Japan, 66, 0, 478-478, Japanese, 1342-8349, 110008713949, AA11439205 - 26aPS-35 Temperature dependence of current-induced domain wall (DW) motion in Co/Ni nano-wires II
Ueda K; Ono T; Koyama T; Chiba D; Tanigawa H; Fukami S; Suzuki T; Ohshima N; Ishiwata N; Nakatani Y
The Physical Society of Japan, 2011, Meeting Abstracts of the Physical Society of Japan, 66, 0, 492-492, Japanese, 1342-8349, 110008714006, AA11439205 - 28aHF-8 Domain Wall Oscillator 2
Kondou K; Nakatani Y; Hiramatsu R; Chiba D; Fukami S; Ishiwata N; Ono T
The Physical Society of Japan, 2011, Meeting Abstracts of the Physical Society of Japan, 66, 0, 515-515, Japanese, 1342-8349, 110008714098, AA11439205 - 21aPS-31 Detection of magnetization precession in domain wall induced by the spin transfer torque in Co/Ni nanowire
Hiramatsu R; Kondou K; Koyama T; Chiba D; Fukami S; Ishiwata N; Nakatani Y; Ono T
The Physical Society of Japan, 2011, Meeting Abstracts of the Physical Society of Japan, 66, 0, 379-379, Japanese, 1342-8349, 110008758630, AA11439205 - 23aRA-7 Realization of Vortex Core Memory Cell
Nakano K; Chiba D; Ohshima N; Kasai S; Sato T; Nakatani Y; Sekiguchi K; Kobayashi K; Ono T
The Physical Society of Japan, 2011, Meeting Abstracts of the Physical Society of Japan, 66, 0, 441-441, Japanese, 1342-8349, 110008758864, AA11439205 - 23pRA-4 Temperature dependence of current-induced domain wall motion in perpendicularly magnetized Co/Ni nanowires
Ueda K; Ono T; Koyama T; Chiba D; Fukami S; Tanigawa H; Suzuki T; Oshima N; Ishiwata N; Nakatani Y
The Physical Society of Japan, 2011, Meeting Abstracts of the Physical Society of Japan, 66, 0, 450-450, Japanese, 1342-8349, 110008758898, AA11439205 - 23pRA-5 Effect of external magnetic field on threshold current density for current-induced domain wall displacement II
Koyama T; Ono T; Ueda K; Chiba D; Fukami S; Tanigawa H; Suzuki T; Ohshima N; Ishiwata N; Nakatani Y
The Physical Society of Japan, 2011, Meeting Abstracts of the Physical Society of Japan, 66, 0, 450-450, Japanese, 1342-8349, 110008758899, AA11439205 - Current-induced domain wall motion in Co/Ni nano-wires with different Co and Ni thicknesses
K. Ueda; D. Chiba; T. Koyama; G. Yamada; H. Tanigawa; S. Fukami; T. Suzuki; N. Ohshima; N. Ishiwata; Y. Nakatani; T. Ono
01 Jan. 2011, Journal of Physics: Conference Series, 266, 1, 1742-6588, 1742-6596, 79952025378 - 24aWP-2 Dependence of vortex resonant frequency on magnetic structure in Fe_<19>Ni_<81> ferromagnetic disk
Goto M.; Hata H.; Yamaguchi A.; Nozaki Y.; Nakatani Y.; Yamaoka T.
The Physical Society of Japan (JPS), 18 Aug. 2010, Meeting abstracts of the Physical Society of Japan, 65, 2, 376-376, Japanese, 1342-8349, 110008097873, AA11439205 - Non-linear Vortex Motion Induced by the Simultaneous Application of rf and dc Currents in a Micron-sized Fe19Ni81 Disk
A. Yamaguchi; K. Motoi; H. Miyajima; T. Sato; Y. Nakatani
2010, IEEE Transactions on Magnetics 11th Joint MMM-Intermag, 46, 6, 1994-1997, English, 0018-9464, 1941-0069, 80021054412, WOS:000278037800186 - 20aPS-28 Reduction of threshold current density for domain wall displacement by shape control of wire
Koyama T; Nakatani Y; Ono T; Ueda K; Yamada G; Chiba D; Tanigawa H; Fukami S; Suzuki T; Ohshima N; Ishiwata N
The Physical Society of Japan, 2010, Meeting Abstracts of the Physical Society of Japan, 65, 0, 455-455, Japanese, 1342-8349, 110007654927, AA11439205 - 20pGJ-3 Current-induced domain wall motion in Co/Ni nano-wires with different Co and Ni thickness
Ueda K; Nakatani Y; Ono T; Koyama T; Yamada G; Chiba D; Tanigawa H; Fukami S; Suzuki T; Ohshima N; Ishiwata N
The Physical Society of Japan, 2010, Meeting Abstracts of the Physical Society of Japan, 65, 0, 466-466, Japanese, 1342-8349, 110007655053, AA11439205 - 20pGJ-4 Current-induced motion of multi domain walls in a Co/Ni wire with perpendicular magnetic anisotropy II
Yamada G; Nakatani Y; Ono T; Koyama T; Ueda K; Chiba D; Tanigawa H; Fukami S; Suzuki T; Ohshima N; Ishiwata N
The Physical Society of Japan, 2010, Meeting Abstracts of the Physical Society of Japan, 65, 0, 466-466, Japanese, 1342-8349, 110007655054, AA11439205 - 20pGJ-8 Switching magnetic vortex core by using a resonance state
Nakano K; Chiba D; Ohshima N; Kasai S; Nakatani Y; Sekiguchi K; Kobayashi K; Ono T
The Physical Society of Japan, 2010, Meeting Abstracts of the Physical Society of Japan, 65, 0, 467-467, Japanese, 1342-8349, 110007655058, AA11439205 - 24aWP-4 Switching of the magnetic vortex core by nano-second field pulses : Elliptical dot
Yamada K; Kasai S; Nakatani Y; Sato T; Sekiguchi K; Chiba D; Kobayashi K; Ono T
The Physical Society of Japan, 2010, Meeting Abstracts of the Physical Society of Japan, 65, 0, 376-376, Japanese, 1342-8349, 110008097875, AA11439205 - 24aWP-5 Effect of external magnetic field on threshold current density for current-induced domain wall displacement
Koyama T; Ono T; Ueda K; Chiba D; Tanigawa H; Fukami S; Suzuki T; Ohshima N; Ishiwata N; Nakatani Y
The Physical Society of Japan, 2010, Meeting Abstracts of the Physical Society of Japan, 65, 0, 377-377, Japanese, 1342-8349, 110008097876, AA11439205 - 25aPS-34 Domain Wall Oscillator
Kondou K; Nakatani Y; Chiba D; Fukami S; Ishiwata N; Ono T
The Physical Society of Japan, 2010, Meeting Abstracts of the Physical Society of Japan, 65, 0, 406-406, Japanese, 1342-8349, 110008097979, AA11439205 - 25aPS-43 Temperature dependence of current-induced domain wall (DW) motion in Co/Ni nano-wires
Ueda K; Ono T; Koyama T; Chiba D; Tanigawa H; Fukami S; Suzuki T; Ohshima N; Ishiwata N; Nakatani Y
The Physical Society of Japan, 2010, Meeting Abstracts of the Physical Society of Japan, 65, 0, 408-408, Japanese, 1342-8349, 110008097988, AA11439205 - Micromagnetics Simulation IV : Chapter 4 The Thermal Effect
HAYASHI N.; UESAKA Y.; NAKATANI Y.; FUKUSHIMA H.
日本磁気学会, 01 Jan. 2009, Magnetics Japan, 4, 1, 43-51, Japanese, 1880-7208, 10024834704, AA1211610X - 27aTF-10 Real-time detection of the current induced vortex dynamics by using the TMR effect
Nakano K; Nakatani Y; Ohshima N; Kasai S; Kobayashi K; Ono T
The Physical Society of Japan, 2009, Meeting Abstracts of the Physical Society of Japan, 64, 0, 430-430, Japanese, 1342-8349, 110007371276, AA11439205 - 27pTF-1 Real-Time Detection of the Magnetic Domain Wall Dynamics
Kondou K; Tanigawa H; Kasai S; Ohshima N; Nakatani Y; Kobayashi K; Ono T
The Physical Society of Japan, 2009, Meeting Abstracts of the Physical Society of Japan, 64, 0, 450-450, Japanese, 1342-8349, 110007371349, AA11439205 - 27pTF-2 Current-driven domain wall motion in Co/Ni wires with perpendicular magnetic anisotropy
Koyama T; Ono T; Tanigawa H; Yamada G; Ohshima N; Fukami S; Ishiwata N; Chiba D; Kasai S; Nakatani Y
The Physical Society of Japan, 2009, Meeting Abstracts of the Physical Society of Japan, 64, 0, 451-451, Japanese, 1342-8349, 110007371350, AA11439205 - 28aPS-101 Switching of the magnetic vortex core by nano-second current pulses : Elliptical dot
Yamada K; Kasai S; Nakatani Y; Kobayashi K; Kohno H; Thiaville Andre; Ono T
The Physical Society of Japan, 2009, Meeting Abstracts of the Physical Society of Japan, 64, 0, 480-480, Japanese, 1342-8349, 110007371469, AA11439205 - 28aPS-108 Current-induced domain wall motion in Co/Ni wires with perpendicular magnetic anisotropy
Tanigawa H; Ono T; Koyama T; Yamada G; Chiba D; Kasai S; Ohshima N; Fukami S; Ishiwata N; Nakatani Y
The Physical Society of Japan, 2009, Meeting Abstracts of the Physical Society of Japan, 64, 0, 482-482, Japanese, 1342-8349, 110007371476, AA11439205 - 28aPS-112 Injection of a single domain wall into a Co/Ni wire with perpendicular magnetic anisotropy
Yamada G; Ono T; Koyama T; Tanigawa H; Ohshima N; Fukami S; Ishiwata N; Chiba D; Kasai S; Nakatani Y
The Physical Society of Japan, 2009, Meeting Abstracts of the Physical Society of Japan, 64, 0, 483-483, Japanese, 1342-8349, 110007371479, AA11439205 - 25pPSA-27 Magnetic anisotropy constant of perpendicularly magnetized Co/Ni nano-wires
Ueda K; Nakatani Y; Ono T; Koyama T; Yamada G; Chiba D; Tanigawa H; Fukami S; Suzuki T; Ohshima N; Ishiwata N
The Physical Society of Japan, 2009, Meeting Abstracts of the Physical Society of Japan, 64, 0, 344-344, Japanese, 1342-8349, 110007497222, AA11439205 - 25pPSA-29 Current-induced motion of multi domain walls in a Co/Ni wire with perpendicular magnetic anisotropy
Yamada G; Nakatani Y; Ono T; Koyama T; Ueda K; Tanigawa H; Fukami S; Suzuki T; Ohshima N; Ishiwata N; Chiba D
The Physical Society of Japan, 2009, Meeting Abstracts of the Physical Society of Japan, 64, 0, 344-344, Japanese, 1342-8349, 110007497224, AA11439205 - 27aRA-4 Domain Wall Motion in High Magnetic Field
Kondou K; Nakatani Y; Ohshima N; Kasai S; Chiba D; Kobayashi K; Ono T
The Physical Society of Japan, 2009, Meeting Abstracts of the Physical Society of Japan, 64, 0, 369-369, Japanese, 1342-8349, 110007497318, AA11439205 - 27aRA-5 Current-induced domain wall motion in Co/Ni wire in magnetic field
Koyama T; Nakatani Y; Ono T; Yamada G; Ueda K; Tanigawa H; Fukami S; Suzuki T; Ohshima N; Ishiwata N; Chiba D
The Physical Society of Japan, 2009, Meeting Abstracts of the Physical Society of Japan, 64, 0, 369-369, Japanese, 1342-8349, 110007497319, AA11439205 - 27aRA-8 Real-time detection of the current induced vortex dynamics by using an MTJ
Nakano K; Kasai S; Nakatani Y; Ohshima N; Sekiguchi K; Chiba D; Kobayashi K; Ono T
The Physical Society of Japan, 2009, Meeting Abstracts of the Physical Society of Japan, 64, 0, 370-370, Japanese, 1342-8349, 110007497322, AA11439205 - Micromagnetics Simulation III : Chapter 3 Numerical Solution to Landau-Lifshitz-Gilbert Equation
HAYASHI N.; UESAKA Y.; NAKATANI Y.; FUKUSHIMA H.
日本磁気学会, 01 Oct. 2008, Magnetics Japan, 3, 10, 481-488, Japanese, 1880-7208, 10024327237, AA1211610X - Micromagnetics Simulation II : Chapter 2 Finite-Difference Method
HAYASHI N.; UESAKA Y.; NAKATANI Y.; FUKUSHIMA H.
日本磁気学会, 01 Jul. 2008, Magnetics Japan, 3, 7, 334-341, Japanese, 1880-7208, 10021155430, AA1211610X - Micromagnetics Simulation I : Chapter 1 Analytic Solution
HAYASHI N.; UESAKA Y.; NAKATANI Y.; FUKUSHIMA H.
日本磁気学会, 01 Apr. 2008, Magnetics Japan, 3, 4, 193-199, Japanese, 1880-7208, 10021154980, AA1211610X - 24aWL-12 Nucleation and Dynamics of Magnetic Vortices under Spin Current
Nakatani Y.; Shibata J.; Tatara G.; Kohno H.; Thiaville A.; Miltat J.
The Physical Society of Japan (JPS), 29 Feb. 2008, Meeting abstracts of the Physical Society of Japan, 63, 1, 476-476, Japanese, 1342-8349, 110007192049, AA11439205 - 21pQG-6 Stochastic pinning of domain wall driven by an external magnetic field
Tanigawa H; Koyama T; Bartkowiak Maciej; Nakatani Y; Kasai S; Ono T
The Physical Society of Japan, 2008, Meeting Abstracts of the Physical Society of Japan, 63, 0, 379-379, Japanese, 1342-8349, 110006983862, AA11439205 - 21pQG-9 Switching of the magnetic vortex core by nano-second current pulses II
Yamada K; Kasai S; Nakatani Y; Kobayashi K; Kohno H; Thiaville Andre; Ono T
The Physical Society of Japan, 2008, Meeting Abstracts of the Physical Society of Japan, 63, 0, 380-380, Japanese, 1342-8349, 110006983865, AA11439205 - 21pQG-14 Real-time detection of the current induced vortex dynamics by using the TMR effect
Nakano K; Nakatani Y; Ohshima N; Kasai S; Kobayashi K; Ono T
The Physical Society of Japan, 2008, Meeting Abstracts of the Physical Society of Japan, 63, 0, 381-381, Japanese, 1342-8349, 110006983870, AA11439205 - 24aWL-11 Real-time and real space imaging of the magnetic vortex resonant motion in a ferromagnetic circular disk
Kasai S; Fischer Peter; Im Mi-Young; Yamada K; Nakatani Y; Oshima K; Kobayashi K; Kohno H; Ono T
The Physical Society of Japan, 2008, Meeting Abstracts of the Physical Society of Japan, 63, 0, 476-476, Japanese, 1342-8349, 110007192048, AA11439205 - 23aPS-29 Real-time detection of the current induced vortex dynamics by using the TMR effect
Nakano K; Nakatani Y; Oshima N; Kasai S; Kobayashi K; Ono T
The Physical Society of Japan, 2008, Meeting Abstracts of the Physical Society of Japan, 63, 0, 431-431, Japanese, 1342-8349, 110007195859, AA11439205 - 23aPS-28 Switching of the magnetic vortex core by nano-second current pulses II
Yamada K; Kasai S; Nakatani Y; Kobayashi K; Kohno H; Thiaville Andre; Ono T
The Physical Society of Japan, 2008, Meeting Abstracts of the Physical Society of Japan, 63, 0, 431-431, Japanese, 1342-8349, 110007195860, AA11439205 - 24aWL-8 単一磁壁ダイナミクスの実時間観測(24aWL 微小領域磁性,領域3(磁性,磁気共鳴))
近藤 浩太; 谷川 博信; 葛西 伸哉; 大嶋 則和; 仲谷 栄伸; 小林 研介; 小野 輝男
一般社団法人 日本物理学会, 2008, 日本物理学会講演概要集, 63, 0, 475-475, Japanese, 1342-8349, 110007195982, AA11439205 - Computer Simulation of Spin Polarized Current Induced Magnetic Domain Wall Motion
NAKATANI Y.
日本応用磁気学会, 01 Jun. 2007, Magnetics Japan, 2, 6, 291-299, Japanese, 1880-7208, 10019927969, AA1211610X - 18pZC-9 Electrical switching of vortex core in a magnetic disk
Yamada K; Kasai S; Nakatan Y; Kobayashi K; Kohno H; Thiaville Andre; Ono T
The Physical Society of Japan, 2007, Meeting Abstracts of the Physical Society of Japan, 62, 0, 444-444, Japanese, 1342-8349, 110007140420, AA11439205 - 18pZC-1 Rectifying effect in magnetic nanowires
Yamaeuchi A; Miyajima H; Ono T; Suzuki Y; Nakatani Y; Yuasa S
The Physical Society of Japan, 2007, Meeting Abstracts of the Physical Society of Japan, 62, 0, 442-442, Japanese, 1342-8349, 110007140428, AA11439205 - 22pWB-1 Switching of the magnetic vortex core by nano-second current pulses
Yamada K; Kasai S; Nakatani Y; Kobayashi K; Kohno H; Thiaville Andre; Ono T
The Physical Society of Japan, 2007, Meeting Abstracts of the Physical Society of Japan, 62, 0, 486-486, Japanese, 1342-8349, 110007141412, AA11439205 - 29pSC-4 Threshold Current of Domain Wall Motion under Extrinsic Pinning, β-Term and Non-Adiabaticity
Tatara Gen; Takayama Toshihiko; Kohno Hiroshi; Shibata Junya; Nakatani Yoshinobu; Fukuyama Hidetoshi
The Physical Society of Japan (JPS), 04 Mar. 2006, Meeting abstracts of the Physical Society of Japan, 61, 1, 490-490, Japanese, 1342-8349, 110007180896, AA11439205 - Computer simulation of magnetization instability by spin-polarized current injection
NAKATANI Yoshinobu
30 Jan. 2006, 日本応用磁気学会研究会資料, 145, 23-29, Japanese, 1340-7562, 10017264893, AN00351217 - Domain-wall dynamics in nanowires and nanostrips
Andre Thiaville; Yoshinobu Nakatani
2006, SPIN DYNAMICS IN CONFINED MAGNETIC STRUCTURES III, 101, 161-205, English, Book review, 0303-4216, WOS:000241944100005 - 23pXH-4 Magnetization reversal process in a ferromagnetic circular dot under current-induced resonant excitation
Kasai S; Yamada K; Nakatani Y; Kobayashi K; Kohno H; Ono T
The Physical Society of Japan, 2006, Meeting Abstracts of the Physical Society of Japan, 61, 0, 345-345, Japanese, 1342-8349, 110007178873, AA11439205 - 23aPS-29 Current-induced resonance by magnetic vortex : Current intensity dependence
Yamada K; Kasai S; Nakatani Y; Kobayashi K; Kohno H; Ono T
The Physical Society of Japan, 2006, Meeting Abstracts of the Physical Society of Japan, 61, 0, 320-320, Japanese, 1342-8349, 110007183032, AA11439205 - 19pYB-7 Dynamics of a magnetic vortex due to spin current
Shibata J.; Tatara G.; Kohno H.; Nakatani Y.; Otani Y.
The Physical Society of Japan (JPS), 19 Aug. 2005, Meeting abstracts of the Physical Society of Japan, 60, 2, 289-289, Japanese, 1342-8349, 110004538575, AA11439205 - 27aYP-7 Computer simulatoin of magnetic domain wall motion by spin polarized current injection
Nakatani Yoshinobu
The Physical Society of Japan (JPS), 04 Mar. 2005, Meeting abstracts of the Physical Society of Japan, 60, 1, 482-482, Japanese, 1342-8349, 110004535956, AA11439205 - Effect of the quadratic uniaxial anistropy term on the R/W properties of the perpendicular recording media
NAKATANI Yoshinobu; HAYASHI Nobuo; UESAKA Yasutaro; FUKUSHIMA Hiroshi
映像情報メディア学会, 10 Feb. 2005, ITE technical report, 29, 12, 11-16, Japanese, 1342-6893, 10015517027, AN1059086X - Effect of the quadratic uniaxial anistropy term on the R/W properties of the perpendicular recording media
NAKATANI Yoshinobu; HAYASHI Nobuo; UESAKA Yasutaro; FUKUSHIMA Hiroshi
The method which utilizes the quadratic uniaxial anistropy term to improve the thermal stability in the recording media was proposed. In this method, the thermal stability can be improved without increasing the write field. But it was predicted that the write field increases as K_2 term is increased when the easy axis of the magnetic moment and the write field is not parallel. In this paper, the effect of the quadratic uniaxial anistropy term on the write field was investigated by computer simulation. The results show that the read/write properties change by the effect of the term because the angle is large, therfore it is found that the write field was changed by the term., The Institute of Electronics, Information and Communication Engineers, 10 Feb. 2005, IEICE technical report. Magnetic recording, 104, 652, 11-16, Japanese, 0913-5685, 110003205543, AN10013050 - 電流による磁壁移動
多々良源; 河野浩; 柴田絢也; 仲谷栄伸; 山口明啓; 小野輝男
2005, 応用物理学会誌,74,1598-1602 (2005). 応用物理学学会, 74, 1598 - The magnetization reversal simulation of a perpendicular magnetization film
NISHIMURA K.; ENDO H.; UESAKA Y.; NAKATANI Y.; HAYASHI N.; FUKUSHIMA H.
21 Sep. 2004, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 28, 474-474, Japanese, 10013769918, AN10269644 - Magnetization Reversal of Single-Domain Particles Studied by Numerically Solving the Fokker-Planck Equation
FUKUSHIMA H.; UESAKA Y.; NAKATANI Y.; HAYASHI N.
The magnetization reversal of single-domain particles at finite temperatures is investigated by numerically solving the Fokker-Planck equation. The equation has singularity at two particular positions. For an axially symmetric system, the problem is surmounted by introducing a novel probability function. For a non-axially symmetric system, it is overcome by using the Cartesian coordinates at these points. The methods above are validated by calculating frequency prefactors and comparing them with those from approximate analytic formulas. For the axially symmetric system, the dependence of the switching time on parameters such as the applied field, the temperature, and the volume is expressed as an experimental formula. For the non-axially symmetric case, assuming that the oblique angle of an applied field to the easy axis is a few degrees, the solution is expanded in a truncated Fourier series. The dependence of the switching time on the applied field and the damping constant is calculated. The effect of a gyromagnetic term in the equation on the switching time is also studied., 日本応用磁気学会, 01 Sep. 2004, Journal of Magnetics Society of Japan, 28, 9, 957-962, Japanese, 0285-0192, 110002809830, AN0031390X - Measurement method of magnetic anisotropy energy constant 2
HIROSE K.; ENDO H.; UESAKA Y.; NAKATANI Y.; HAYASHI N.; FUKUSHIMA H.
01 Sep. 2003, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 27, 217-217, Japanese, 1340-8100, 10015761496, AN10269644 - Measurement of easy axis distribution
SANGUU T.; ENDO H.; UESAKA Y.; NAKATANI Y.; HAYASHI N.; FUKUSHIMA H.
01 Sep. 2003, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 27, 216-216, Japanese, 1340-8100, 10015761493, AN10269644 - Computer simulation of switching time of perpendicular film
YOSHINO M.; ENDO H.; UESAKA Y.; NAKATANI Y.; HAYASHI N.; FUKUSHIMA H.
01 Sep. 2003, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 27, 98-98, Japanese, 1340-8100, 10015761181, AN10269644 - Compuater simulation of domain wall motion with Bloch point in nano wire
NAKATANI Y.; HAYASHI N.
01 Sep. 2002, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 26, 99-99, Japanese, 1340-8100, 10015759915, AN10269644 - Effect of magnetization on read/write properties of AFC media
NAKATANI Y.; HAYASHI N.; UESAKA Y.; FUKUSHIMA H.
01 Sep. 2002, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 26, 175-175, Japanese, 1340-8100, 10015760147, AN10269644 - Micromagnetic Study of Magnetization Configuration on Single Pole Type Head
MOCHIZUKI M.; ISHIKAWA C.; IDE H.; NAKAMOTO K.; NAKATANI Y.; HAYASHI N.
01 Sep. 2002, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 26, 438-438, Japanese, 1340-8100, 10015760837, AN10269644 - Thermal stability of AFC recording media
NAKATANI Yoshinobu
07 Mar. 2002, 日本応用磁気学会研究会資料, 124, 17-24, Japanese, 1340-7562, 10007792786, AN00351217 - Computer simulation of switching time of magnetic particle
TAKAHASI T.; FUJIWARA T.; ENDO H.; UESAKA Y.; NAKATANI Y.; HAYASHI N.; FUKUSHIMA H.
01 Sep. 2001, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 25, 142-142, Japanese, 1340-8100, 10007796786, AN10269644 - Measurement of anisotropy field and easy axis distribution
TOMIZAWA H.; ENDO H.; UESAKA Y.; NAKATANI Y.; HAYASHI N.; FUKUSHIMA H.
01 Sep. 2001, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 25, 141-141, Japanese, 1340-8100, 10007796784, AN10269644 - Effect of thermal fluctuation of AFC recording media
NAKATANI Y.; HAYASHI N.; UESAKA Y.; FUKUSHIMA H.
01 Sep. 2001, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 25, 406-406, Japanese, 1340-8100, 10007797506, AN10269644 - Read/write properties of AFC recording media
NAKATANI Y.; HAYASHI N.; UESAKA Y.; FUKUSHIMA H.
01 Sep. 2001, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 25, 405-405, Japanese, 1340-8100, 10007797503, AN10269644 - Compuater simulation model for AFC recording media
NAKATANI Y.; HAYASHI N.; UESAKA Y.; FUKUSHIMA H.
01 Sep. 2001, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 25, 404-404, Japanese, 1340-8100, 10007797501, AN10269644 - Exchange interaction of single layer perpendicular media and R/W properties
UESAKA Y.; ENDO H.; NAKATANI H. Y.; HAYASHI N.; FUKUSHIMA H.
01 Sep. 2001, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 25, 403-403, Japanese, 1340-8100, 10007797499, AN10269644 - Galvanomagnetic effect of permalloy nano-ring wire II magnetization properties
Niiyama T.; Kasai S.; Hirota Y.; Miyajima H.; Nakatani Y.; Hayashi N.
The Physical Society of Japan (JPS), 09 Mar. 2001, Meeting abstracts of the Physical Society of Japan, 56, 1, 415-415, Japanese, 1342-8349, 110002157400, AA11439205 - Computer simulation of magnetization switching of particles with groves
ENDO H.; UESAKA Y.; NAKATANI Y.; HAYASHI N.; FUKUSHIMA H.
01 Sep. 2000, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 24, 104-104, Japanese, 1340-8100, 10007795266, AN10269644 - Influence of particle size and Ku distribution and exchange on thermal stability
AKAGI F.; YOSHIDA K.; NAKATANI Y.; HAYASHI N.
01 Sep. 2000, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 24, 393-393, Japanese, 1340-8100, 10007796103, AN10269644 - Computer simulation of switching field and time of single magnetic particle
ABE R.; ENDO H.; UESAKA Y.; NAKATANI Y.; HAYASHI N.; FUKUSHIMA H.
01 Sep. 2000, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 24, 398-398, Japanese, 1340-8100, 10007796117, AN10269644 - Numerical Solution of LLG Equation by Backward-difference Method
KADOGAKI N.; KAWABATA Y.; NAKATANI Y.; HAYASHI N.
01 Sep. 2000, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 24, 389-389, Japanese, 1340-8100, 10007796092, AN10269644 - Acceleration of LaBonte's Iteration by Multigrid Method
KAWABATA Y.; HIRANO S.; HAYASHI N.; NAKATANI Y.
01 Sep. 2000, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 24, 390-390, Japanese, 1340-8100, 10007796094, AN10269644 - MAMMOS Copy Simulation : Effect of Temperature Distribution
NAKATANI Y.; HAYASHI N.; IMAI S.; AWANO H.; OHTA N.
01 Sep. 2000, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 24, 438-438, Japanese, 1340-8100, 10007796231, AN10269644 - Magnetization Distribution in Displacement Layer on DWDD
NAKATANI Y.; KOBAYASHI T.; SHIRATORI T.
01 Sep. 2000, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 24, 443-443, Japanese, 1340-8100, 10007796247, AN10269644 - Computer Simulation of Magnetic Domain Wall Motion in a Magnetic Strip Line
NAKATANI Y; HAYASHI N; ONO T; MIYAJIMA H
01 Sep. 2000, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 24, 197-197, Japanese, 1340-8100, 10007795573, AN10269644 - Velocity of Magnetic Domain Wall Motion in a Magnetic Strip Line
NAKATANI Y; HAYASHI N; ONO T; MIYAJIMA H
01 Sep. 2000, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 24, 198-198, Japanese, 1340-8100, 10007795576, AN10269644 - Switching field of a fine magnetic particle with surface anisotropy
NAKATANI Y.; HAYASHI N.; UESAKA Y.; KITAKAMI O.; SHIMADA
07 Feb. 2000, 電気学会研究会資料. MAG, マグネティックス研究会, 2000, 1, 37-41, Japanese, 10019056580, AN00346760 - Computer simulation of R/W properties of longitudinal medea
UESAKA Y.; NAKATANI Y.; HAYASHI N.; FUKUSHIMA H.
01 Oct. 1999, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 23, 438-438, Japanese, 10005326275, AN10269644 - Computer Simulation of Wall motion by Wall Energy
NAKATANI Y.; KAMATA K.; KOBAYASHI T.; SHIRATORI T.
01 Oct. 1999, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 23, 84-84, Japanese, 10005325313, AN10269644 - Computer simulation of magnetization switching of particles with various shapes
ENDO H.; UESAKA Y.; NAKATANI Y.; HAYASHI N.
01 Oct. 1999, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 23, 135-135, Japanese, 10005325429, AN10269644 - Grain arrangement model in magnetic recording simulation
OSHIMA T.; NAKAYANI Y.; HAYASHI N.
01 Oct. 1999, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 23, 458-458, Japanese, 10005326330, AN10269644 - Numerical Solution of LLG Equation Based on Basic Relaxation Method
KAWABATA Y.; HIRANO S.; HAYASHI Y.; NAKATANI Y.
01 Oct. 1999, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 23, 454-454, Japanese, 10005326317, AN10269644 - Computer Simulation of frequency factor of fine magnetic particle
NAKATANI Y.; HAYASHI N.; UESAKA Y.; FUKUSHIMA H.
01 Oct. 1999, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 23, 452-452, Japanese, 10005326309, AN10269644 - Numerical Solution of LLG Equation by Multigrid Method
HIRANO S.; KAWABATA Y.; HAYASHI N.; NAKATANI Y.
01 Oct. 1999, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 23, 455-455, Japanese, 10005326321, AN10269644 - Influences of α on recording characteristics at high frequencies
AKAGI F.; IGARASHI M.; YOSHIDA K.; NAKATANI Y.; HAYASHI N.
01 Sep. 1998, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 22, 330-330, Japanese, 10002824750, AN10269644 - Effect of Surface Anistropy on Seitching Field of Magnetic Fine Particle
NAKATANI Y.; HAYASHI N.; UESAKA Y.; FUKUSHIMA H.; KITAKAMI O.; SHIMADA Y.
01 Sep. 1998, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 22, 384-384, Japanese, 10002824887, AN10269644 - Anisotropy energy constant of longitudinal media measured by 45 degree method
UESAKA Y.; NAKATANI Y.; HAYASHI N.; FUKUSHIMA H.; INABA N.
01 Sep. 1998, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 22, 471-471, Japanese, 10002825113, AN10269644 - MAMMOS Copy Somulation for Circular Domain
NAKATANI Y.; HAYASHI N.; AWANO H.; OHTA N.
01 Sep. 1998, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 22, 497-497, Japanese, 10002825197, AN10269644 - MAMMOS COpy Simulation for Crescent Shaped Domain
NAKATANI Y.; HAYASHI N.; AWANO H.; OHTA N.
01 Sep. 1998, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 22, 498-498, Japanese, 10002825200, AN10269644 - MAMMOS Copy Simulation(One-Dimensional Case)
GUNJI S.; OSHIMA T.; KAMATA K.; NAKATANI Y.; HAYASHI N.
01 Sep. 1998, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 22, 499-499, Japanese, 10002825204, AN10269644 - MAMMOS Copy Simulation by Laser
KAMATA K.; OSHIMA T.; GUNJI S.; NAKATANI Y.; HAYASHI N.
01 Sep. 1998, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 22, 500-500, Japanese, 10002825208, AN10269644 - Simulation of Thermal Fluctuation of Magnetic Recording Media
UESAKA Y.; NAKATANI Y.; HAYASHI N.; FUKUSHIMA H.
Thermal fluctuation of the magnetization and recorded pattern in longitudinal and perpendicular recording media was investigated by using the Monte Carlo simulation method. Distribution of the grain size in a medium increases the effect of thermal fluctuation of the magnetization and recorded pattern. Perpendicular recording is superior to longitudinal recording from the thermal fluctuation point of view. In longitudinal recording after three years decay, it is difficult to obtain a higher recording density than 10 Gb/in^2 at 423 kFCl. In perpendicular recording, the recording density of 50 Gb/in^2 is possible to be obtained., 日本応用磁気学会, 01 Jul. 1998, Journal of Magnetics Society of Japan, 22, 7, 1111-1118, Japanese, 0285-0192, 110002810110, AN0031390X - Computer Simulation of Effect of Thermal Fluctuation on Magnetic Recording Media
NAKATANI Y.; HAYASHI N.; UESAKA Y.; FUKUSHIMA H.
29 Jan. 1998, 日本応用磁気学会研究会資料, 103, 13-19, Japanese, 1340-7562, 10002521165, AN00351217 - Effefct of grain shape in magnetic recording media simulation
NAKATANI Yoshinobu; HAYASHI Nobuo; UESAKA Yasutaro; FUKUSHIMA Hiroshi
01 Oct. 1997, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 21, 260-260, Japanese, 10002730510, AN10269644 - Solving LLG equation for low-dissipation media
KAWASHIMA Y.; HAYASHI N.; NAKATANI Y.
01 Oct. 1997, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 21, 269-269, Japanese, 10002730533, AN10269644 - Influence of hard magnet film stractures on read characteristics of MR heads.
ISHIKAWA C.; TOTUSUKA K.; IGARASHI M.; SUZUKI Y.; NAKATANI Y.; HAYASHI N.
01 Oct. 1997, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 21, 414-414, Japanese, 10002730899, AN10269644 - Monte Carlo Simulation of Thermal Fluctuation in Longitudinal and Perpendicular Recording Media
UESAKA Yasutaro; TAKAHASHI Yoshio; NAKATANI Yoshinobu; HAYASHI Nobuo; FUKUSHIMA Hiroshi
Thermal fluctuation in magnetization of longitudinal and perpendicular recording media was calculated using a Monte Carlo simulation method. Distribution of grain size in a medium increases the effect of thermal fluctuation in magnetization. Perpendicular recording is superior to longitudinal recording from thermal fluctuation point of view. In longitudinal recording, the effect of thermal fluctuation increases with increasing recording density, but in perpendicular recording the effect decreases with increasing recording density., The Institute of Image Information and Television Engineers, 21 Nov. 1996, ITEJ Technical Report, 20, 61, 7-13, Japanese, 0386-4227, 110003680572, AN00352231 - Monte Carlo simulation of recording media
UESAKA Yasutaro; NAKATANI Yoshinobu; HAYASHI Nobuo; FUKUSHIMA Hiroshi
01 Sep. 1996, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 20, 16-16, Japanese, 10002728782, AN10269644 - Read/write properties of perpendicular recording media by thermal fluctuation
NAKATANI Yoshinobu; HAYASHI Nobuo; UESAKA Yasutaro; FUKUSHIMA Hiroshi
01 Sep. 1996, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 20, 18-18, Japanese, 10002728787, AN10269644 - Read/write properties of longitudinal recording media by thermal fluctuation
NAKATANI Yoshinobu; HAYASHI Nobuo; UESAKA Yasutaro; FUKUSHIMA Hiroshi
01 Sep. 1996, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 20, 17-17, Japanese, 10002728784, AN10269644 - Monte Carlo Simulation of Thermal Fluctuation Aftereffect
UESAKA Y.; NAKATANI Y.; HAYASHI N.; FUKUSHIMA H.
01 Sep. 1995, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 19, 405-405, Japanese, 10002646982, AN10269644 - Computer Simulation of Thermal Fractuation After Effect using Langeving Equation
NAKATANI Yoshinobu; HAYASHI Nobuo; UESAKA Yasutaro
01 Sep. 1995, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 19, 406-406, Japanese, 10002646986, AN10269644 - Analysis of output and magnetization configuration of shielded MR head
FUJIMOTO K.; TOTSUKA K.; UESAKA Y.; SAITOH I.; FUKUI H.; YOSHIHARA I.; NAKATANI Y.; HAYASHI N.
01 Sep. 1995, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 19, 224-224, Japanese, 10002646503, AN10269644 - Dependence of output characteristics on casy direction in MR head. -Simulation-
ISHIKAWA C.; FUJIMOTO K.; UESAKA Y.; NAKATANI Y.; HAYASHI N.
01 Sep. 1995, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan, 19, 220-220, Japanese, 10002646493, AN10269644 - Computer Simulation of Output and Magnetization configuration of MR Sensor Dependence of MR response to a cycle of transverse external field on direction of easy magnetization of SAL
FUJIMOTO Kazuhisa; TOTSUKA Kaori; UESAKA Yasutaro; FUKUI Hiroshi; NAKATANI Yoshinobu; HAYASHI Nobuo
In an exchange biased magneto-resistive (MR) sensor with a soft adjacent layer (SAL), a MR response to a cycle of a transverse external field has a hysteresis due to a vortex nucleated at a corner of the sensing area of the SAL. To prevent the nucleation of the vortex, the dependence of the MR response on the direction of the easy magnetization of the SAL has been investigated using a computer simulation. It has been found that the MR response has no hysteresis if the direction of the easy magnetization of the SAL tilts 30 to 60 degrees from the longitudinal direction of the sensor to the direction of the magnetization of the SAL in the biased state., The Institute of Electronics, Information and Communication Engineers, 19 May 1995, IEICE technical report. Magnetic recording, 95, 49, 1-8, Japanese, 110003186179, AN10013050 - Numerical simulation of magnetization reversal using super - computer
Uesaka Yasutaro; Fujimoto Kazuhisa; Yoshihara Ikuo; Nakatani Yoshinobu; Hayashi Nobuo
Magnetic structure and magnetization reversal mechaism of magneto-resistive head were analysed by using super-computer. Magnetic films were divided into rectangular cells and each magnetic moment was assumed to precess according to the Landau-Lifshitz-Gilbert equation. For the demagnetizing field calculation, which is the most time cosuming process, Fast Fourier Transform was used. Then, the computation time became less than 1/20 than the time for the direct calculation method. The effect of uniform applied field on output was calculated and small peaks due to magnetization reversals of SAL (Soft Adjacent Layer) were observed., Information Processing Society of Japan (IPSJ), 27 Oct. 1994, IPSJ SIG Notes, 1994, 92, 9-16, Japanese, 110002932150, AN10463942 - Computer simulation of thin-film media noise
Yoshida Kazuetsu; Uesaka Yasutaro; Hara Miki; Nakatani Yoshinobu; Hayashi Nobuo
Computer simulation using the autocorreelation function along the track direction was used to investigate the relationship between thin-film media noise and both the orientation of easy axis and the exchange interaction.Preferentially orienting the easy axis in the circumferential direction decreases the media noise and increases the strength of output signal.On the other hand,exchange interaction slightly increases media noise and reduces the signal-to-noise ratio.Preferential orientation of the easy axis,however,improves the signal-to-noise ratio more effectively than does preventing intergranular exchange interaction., The Institute of Electronics, Information and Communication Engineers, 19 May 1993, IEICE technical report. Magnetic recording, 93, 29, 29-35, Japanese, 110003186284, AN10013050 - 8)Dynamical Calculation of Magnetization Reversal in Small Particles
上坂 保太郎; 仲谷 栄伸; 林 信夫
The Institute of Image Information and Television Engineers, 20 Nov. 1992, The Journal of the Institute of Television Engineers of Japan, 46, 11, 1526-1526, Japanese, 0386-6831, 110003675411, AN00151466
Lectures, oral presentations, etc.
- Simulation of spin-orbit-torque switching of a perpendicular nanomagnet with narrow current wire
Joshiro Watanabe; Keisuke Yamada; Yoshinobu Nakatani
Poster presentation, English, ICM2024
03 Jul. 2024 - Domain Wall Motion Enhancement in Re-rich/TM-rich GdFeCo and GdFe Nanowires by Applying Laser-Annealing Process
Mojtaba Mohammadi; Sina Ranjbar; Satoshi Sumi; Kenji Tanabe; Yoshinobu Nakatani; Hiroyuki Awano
Poster presentation, English, ICM2024
2024 - Simulation of spin-orbit-torque switching of a perpendicular nanomagnet assited by DMI
J. Watanabe; K. Yamada; Y. Nakatani
Intermag2023, Peer-reviewed
May 2023 - Logic operations of magnetic-skyrmion chirality via a branched nanowire
Y. Nakatani; K. Yamada; A. Hirohata
Intermag2023, Peer-reviewed
May 2023 - Current-niduced magnetic octupole domain-wall dynamics
M. Wu; T. Chen; T. Nomoto; H. Isshiki; Y. Nakatani; T. Higo; T.Tomita; K. Kondou; R. Arita; S. Nakatsuji; Y. Otani
Oral presentation, MMM2022, Peer-reviewed
Oct. 2022 - Thermal Agitation of Magnetization Dynamics Induced by Electric-field
S. Kanai; Y. Nakatani; F. Matsukura; H. Ohno
JEMS2022, Peer-reviewed
26 Jun. 2022 - Thermal Effect in Electric-field Induced Magnetization Dynamics in a Nanoscale Magnetic Tunnel Junction
S. Kanai; Y. Nakatani; F. Matsukura; H. Ohno
ICMFS2022, Peer-reviewed
13 Jun. 2022 - Multiple-valued Memory Utilized Chiral Magnetic Skyrmion
J. Watanabe; K. Yamada; and; Y. Nakatani
ICMFS2022, Peer-reviewed
12 Jun. 2022 - Controlling antiferromagnetic skyrmion motions in an angelfish racetrack by electric field
K. Hamada; K. Nishi; K. Yamada; Y. Nakatani
ICMFS2022, Peer-reviewed
12 Jun. 2022 - Simulation of the switching probability in nanomagnets with perpendicular anisotropy",
K. Kawakami; K. Yamada; Y. Nakatani
ICMFS2022, Peer-reviewed
12 Jun. 2022 - Electrical discrimination of magnetic-skyrmion chirality via spin-orbit and-transfer torques in a branched nanowire
K. Yamada; A. Hirohata; Y. Nakatani
2022 Joint MMM-Intermag Conference, Peer-reviewed
Jan. 2022 - Determination of the Dzyaloshinskii-Moriya interaction from a single magnetic domain image using machine learning
K. Tanabe; S. Hasegawa; M. Hayashi; M. Kawaguchi; T. Sawa; K. Yamada; Y. Nakatani
2021 Intermag Conference, Peer-reviewed
Apr. 2021 - Discrimination of skyrmion chirality via spin-orbit and -transfer torques for logic operation
K. Yamada; A. Hirohata; Y. Nakatani
IOP institute of Physics, CRIM 2021: Magnetic Skyrmions,, Peer-reviewed
2021 - Computer simulation of domain wall motion induced by a slope electric field.
S. Murayama; K. Yamada; Y. Nakatani
English, 2015 IEEE MAGNETICS CONFERENCE (INTERMAG), IEEE
2015
2015 2015 - 9pBF-7 Domain wall dynamics in the presence of the Dzyaloshinskii-Moriya interaction
Yoshimura Yoko; Kim Kab-Jin; Taniguchi Takuya; Ueda Kohei; Hiramatsu Ryo; Moriyama Takahiro; Tanigawa Hironobu; Suzuki Tetsuhiro; Kariyada Eiji; Nakatani Yoshinobu; Ono Teruo
Japanese, Meeting abstracts of the Physical Society of Japan, The Physical Society of Japan (JPS)
22 Aug. 2014
22 Aug. 2014- 22 Aug. 2014 - 9pBF-5 Switching of a Magnetic Vortex Core in a Pac-man Disk using a Single Current Pulse
Yamada Keisuke; Sato Tomonori; Nakatani Yoshinobu
Japanese, Meeting abstracts of the Physical Society of Japan, The Physical Society of Japan (JPS)
22 Aug. 2014
22 Aug. 2014- 22 Aug. 2014 - 28aAF-4 Switching of the Magnetic Vortex Core in a Pac-man Disk
Yamada Keisuke; Sato Tomonori; Nakatani Yoshinobu
Japanese, Meeting abstracts of the Physical Society of Japan, The Physical Society of Japan (JPS)
05 Mar. 2014
05 Mar. 2014- 05 Mar. 2014 - 28aAF-3 Observation of metastable bound state between domain walls in an asymmetric Co/Ni nanowire II
Hiramatsu R.; Kim Kab-Jin; Hata H.; Taniguchi T.; Tanigawa H.; Kariyada H.; Suzuki T.; Nakatani Y.; Moriyama T.; Ono T.
Japanese, Meeting abstracts of the Physical Society of Japan, The Physical Society of Japan (JPS)
05 Mar. 2014
05 Mar. 2014- 05 Mar. 2014 - Influence of spin Hall effect for current-induced domain wall motion in a perpendicularly magnetized Co/Ni nanowire
Yoshimura Y.; Koyama T.; Moriyama T.; Kim Kab-Jin; Chiba D.; Nakatani Y.; Fukami S.; Yamanouchi M.; Ohno H.; Ono T.
Japanese, Meeting abstracts of the Physical Society of Japan, The Physical Society of Japan (JPS)
26 Aug. 2013
26 Aug. 2013- 26 Aug. 2013 - Switching of the Magnetic Vortex Core in Elliptical Disks by Nano-second Field Pulses
Yamada Keisuke; Sato Tomonori; Nakatani Yoshinobu; Kasai Shinya; Chiba Daichi; Kobayashi Kensuke; Thiaville Andre; Ono Teruo
Japanese, Meeting abstracts of the Physical Society of Japan, The Physical Society of Japan (JPS)
26 Aug. 2013
26 Aug. 2013- 26 Aug. 2013 - Mechanism change of current-induced magnetic domain wall motion in multilayered Co/Ni nanowires
Ueda K.; Kim K-J.; Hiramatsu R.; Moriyama T.; Chiba D.; Tanigawa H.; Kariyada E.; Suzuki T.; Nakatani Y.; Ono T.
Japanese, Meeting abstracts of the Physical Society of Japan, The Physical Society of Japan (JPS)
26 Aug. 2013
26 Aug. 2013- 26 Aug. 2013 - 26aPS-18 Detection of magnetization rotation in domain wall induced by spin transfer torque in Co/Ni nanowire
Kim Kab-Jin
Japanese, Meeting abstracts of the Physical Society of Japan, The Physical Society of Japan (JPS)
26 Mar. 2013
26 Mar. 2013- 26 Mar. 2013 - 27pXA-6 Current pulse width dependence of magnetic domain wall motion in the presence of bias magnetic field
Kim Kab-Jin; Chiba D.; Nakatani Y.; Fukami S.; Yamanouchi M.; Ohno H.; Ono T.
English, Meeting abstracts of the Physical Society of Japan, The Physical Society of Japan (JPS)
26 Mar. 2013
26 Mar. 2013- 26 Mar. 2013 - 27pXA-5 Temperature Dependence of Current-Induced Magnetic Domain Wall Motion in a Multilayered Co/Ni Nanowire with MgO Cap
上田 浩平; 小野 輝男; 平松 亮; キムカブジン; 森山 貴広; 千葉 大地; 谷川 博信; 苅屋田 英嗣; 鈴木 哲広; 仲谷 栄伸
Japanese, Meeting Abstracts of the Physical Society of Japan, The Physical Society of Japan, http://ci.nii.ac.jp/naid/110009644376
2013
2013 2013 - 26aPS-17 Current-induced domain wall motion in a perpendicularly magnetized Co/Ni nanowire under in-plane magnetic field (III)
Yoshimura Y; Koyama T; Moriyama T; Chiba D; Tanigawa H; Kariyada E; Suzuki T; Nakatani Y; Ono T
Japanese, Meeting Abstracts of the Physical Society of Japan, The Physical Society of Japan, http://ci.nii.ac.jp/naid/110009644236
2013
2013 2013 - 27aAA-3 Manipulation of the vortex core damping motion
Nakano K; Chiba D; Ohshima N; Kasai S; Sato T; Nakatani Y; Sekiguchi K; Kobayashi K; Ono T
Japanese, Meeting Abstracts of the Physical Society of Japan, The Physical Society of Japan, http://ci.nii.ac.jp/naid/110009566772
2012
2012 2012 - 24aPS-29 Additivity of magnetic domain wall velocities induced by current and field
Koyama T; Ueda K; Chiba D; Fukami S; Ishiwata N; Kohno H; Nakatani Y; Kobayashi K; Ono T
Japanese, Meeting Abstracts of the Physical Society of Japan, The Physical Society of Japan, http://ci.nii.ac.jp/naid/110009566583
2012
2012 2012 - 24aPS-28 Detection of magnetization rotation in domain wall induced by spin transfer torque
Hiramatsu R; Kondou K; Koyama T; Chiba D; Fukami S; Ishiwata N; Nakatani Y; Ono T
Japanese, Meeting Abstracts of the Physical Society of Japan, The Physical Society of Japan, http://ci.nii.ac.jp/naid/110009566582
2012
2012 2012 - 27aAA-8 Temperature Dependence of Spin Polarization of Current in Co/Ni Nanowire Estimated from Current-Induced Magnetic Domain Wall Motion
Ueda K; Nakatani Y; Ono T; Koyama T; Hiramatsu R; Chiba D; Fukami S; Tanigawa H; Suzuki T; Ohshima N; Ishiwata N
Japanese, Meeting Abstracts of the Physical Society of Japan, 一般社団法人 日本物理学会, http://ci.nii.ac.jp/naid/110009566777
2012
2012 2012 - 20aCC-10 Current-induced domain wall motion in a perpendicularly magnetized Co/Ni nanowire under in-plane magnetic field (II)
Yoshimura Y; Koyama T; Chiba D; Fukami S; Yamanouchi M; Ohno H; Nakatani Y; Ono T
Japanese, Meeting Abstracts of the Physical Society of Japan, The Physical Society of Japan, http://ci.nii.ac.jp/naid/110009600017
2012
2012 2012 - 27aAA-10 High-field motion of magnetic domain wall in (Co/Ni) nanostrips
Yamada K; Jamet Jean-Pierre; Nakatani Y; Ueda K; Mougin Alexandra; Thiaville Andre; Ono T; Ferre Jacques
Japanese, Meeting Abstracts of the Physical Society of Japan, The Physical Society of Japan, http://ci.nii.ac.jp/naid/110009566779
2012
2012 2012 - 27aAA-9 Current-induced domain wall motion in a perpendicularly magnetized Co/Ni nanowire under in-plane magnetic field
Yoshimura Y; Koyama T; Chiba D; Fukami S; Yamanouchi M; Ohno H; Nakatani Y; Ono T
Japanese, Meeting Abstracts of the Physical Society of Japan, The Physical Society of Japan, http://ci.nii.ac.jp/naid/110009566778
2012
2012 2012 - Influence of hard magnet film stractures on read characteristics of MR heads.
ISHIKAWA C.; TOTUSUKA K.; IGARASHI M.; SUZUKI Y.; NAKATANI Y.; HAYASHI N.
Japanese, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan
01 Oct. 1997
01 Oct. 1997- 01 Oct. 1997 - Solving LLG equation for low-dissipation media
KAWASHIMA Y.; HAYASHI N.; NAKATANI Y.
Japanese, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan
01 Oct. 1997
01 Oct. 1997- 01 Oct. 1997 - Monte Carlo Simulation of Thermal Fluctuation in Longitudinal and Perpendicular Recording Media
UESAKA Yasutaro; TAKAHASHI Yoshio; NAKATANI Yoshinobu; HAYASHI Nobuo; FUKUSHIMA Hiroshi
Japanese, ITEJ Technical Report, The Institute of Image Information and Television Engineers, Thermal fluctuation in magnetization of longitudinal and perpendicular recording media was calculated using a Monte Carlo simulation method. Distribution of grain size in a medium increases the effect of thermal fluctuation in magnetization. Perpendicular recording is superior to longitudinal recording from thermal fluctuation point of view. In longitudinal recording, the effect of thermal fluctuation increases with increasing recording density, but in perpendicular recording the effect decreases with increasing recording density.
21 Nov. 1996
21 Nov. 1996- 21 Nov. 1996 - Read/write properties of longitudinal recording media by thermal fluctuation
NAKATANI Yoshinobu; HAYASHI Nobuo; UESAKA Yasutaro; FUKUSHIMA Hiroshi
Japanese, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan
01 Sep. 1996
01 Sep. 1996- 01 Sep. 1996 - Read/write properties of perpendicular recording media by thermal fluctuation
NAKATANI Yoshinobu; HAYASHI Nobuo; UESAKA Yasutaro; FUKUSHIMA Hiroshi
Japanese, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan
01 Sep. 1996
01 Sep. 1996- 01 Sep. 1996 - Monte Carlo simulation of recording media
UESAKA Yasutaro; NAKATANI Yoshinobu; HAYASHI Nobuo; FUKUSHIMA Hiroshi
Japanese, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan
01 Sep. 1996
01 Sep. 1996- 01 Sep. 1996 - Dependence of output characteristics on casy direction in MR head. -Simulation-
ISHIKAWA C.; FUJIMOTO K.; UESAKA Y.; NAKATANI Y.; HAYASHI N.
Japanese, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan
01 Sep. 1995
01 Sep. 1995- 01 Sep. 1995 - Analysis of output and magnetization configuration of shielded MR head
FUJIMOTO K.; TOTSUKA K.; UESAKA Y.; SAITOH I.; FUKUI H.; YOSHIHARA I.; NAKATANI Y.; HAYASHI N.
Japanese, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan
01 Sep. 1995
01 Sep. 1995- 01 Sep. 1995 - Computer Simulation of Thermal Fractuation After Effect using Langeving Equation
NAKATANI Yoshinobu; HAYASHI Nobuo; UESAKA Yasutaro
Japanese, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan
01 Sep. 1995
01 Sep. 1995- 01 Sep. 1995 - Monte Carlo Simulation of Thermal Fluctuation Aftereffect
UESAKA Y.; NAKATANI Y.; HAYASHI N.; FUKUSHIMA H.
Japanese, 日本応用磁気学会学術講演概要集 = Digest of ... annual conference on magnetics in Japan
01 Sep. 1995
01 Sep. 1995- 01 Sep. 1995 - Computer Simulation of Output and Magnetization configuration of MR Sensor Dependence of MR response to a cycle of transverse external field on direction of easy magnetization of SAL
FUJIMOTO Kazuhisa; TOTSUKA Kaori; UESAKA Yasutaro; FUKUI Hiroshi; NAKATANI Yoshinobu; HAYASHI Nobuo
Japanese, IEICE technical report. Magnetic recording, The Institute of Electronics, Information and Communication Engineers, In an exchange biased magneto-resistive (MR) sensor with a soft adjacent layer (SAL), a MR response to a cycle of a transverse external field has a hysteresis due to a vortex nucleated at a corner of the sensing area of the SAL. To prevent the nucleation of the vortex, the dependence of the MR response on the direction of the easy magnetization of the SAL has been investigated using a computer simulation. It has been found that the MR response has no hysteresis if the direction of the easy magnetization of the SAL tilts 30 to 60 degrees from the longitudinal direction of the sensor to the direction of the magnetization of the SAL in the biased state.
19 May 1995
19 May 1995- 19 May 1995 - Numerical simulation of magnetization reversal using super - computer
Uesaka Yasutaro; Fujimoto Kazuhisa; Yoshihara Ikuo; Nakatani Yoshinobu; Hayashi Nobuo
Japanese, IPSJ SIG Notes, Information Processing Society of Japan (IPSJ), http://id.nii.ac.jp/1001/00029888/, Magnetic structure and magnetization reversal mechaism of magneto-resistive head were analysed by using super-computer. Magnetic films were divided into rectangular cells and each magnetic moment was assumed to precess according to the Landau-Lifshitz-Gilbert equation. For the demagnetizing field calculation, which is the most time cosuming process, Fast Fourier Transform was used. Then, the computation time became less than 1/20 than the time for the direct calculation method. The effect of uniform applied field on output was calculated and small peaks due to magnetization reversals of SAL (Soft Adjacent Layer) were observed.
27 Oct. 1994
27 Oct. 1994- 27 Oct. 1994 - Computer simulation of thin-film media noise
Yoshida Kazuetsu; Uesaka Yasutaro; Hara Miki; Nakatani Yoshinobu; Hayashi Nobuo
Japanese, IEICE technical report. Magnetic recording, The Institute of Electronics, Information and Communication Engineers, Computer simulation using the autocorreelation function along the track direction was used to investigate the relationship between thin-film media noise and both the orientation of easy axis and the exchange interaction.Preferentially orienting the easy axis in the circumferential direction decreases the media noise and increases the strength of output signal.On the other hand,exchange interaction slightly increases media noise and reduces the signal-to-noise ratio.Preferential orientation of the easy axis,however,improves the signal-to-noise ratio more effectively than does preventing intergranular exchange interaction.
19 May 1993
19 May 1993- 19 May 1993 - 8)Dynamical Calculation of Magnetization Reversal in Small Particles
上坂 保太郎; 仲谷 栄伸; 林 信夫
Japanese, The Journal of the Institute of Television Engineers of Japan, The Institute of Image Information and Television Engineers
20 Nov. 1992
20 Nov. 1992- 20 Nov. 1992
Research Themes
- 磁気スキルミオンのカイラリティを利用したメモリ・ロジックデバイスの開発
仲谷 栄伸
日本学術振興会, 科学研究費助成事業 基盤研究(C), 電気通信大学, 基盤研究(C), 23K04526
01 Apr. 2023 - 31 Mar. 2026 - Determination of the magnetic parameter using pattern recognition and machine learning
Yoshinobu Nakatani
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B), The University of Electro-Communications, Grant-in-Aid for Scientific Research (B), We show that machine learning can be used to extract material parameters from a single image obtained in experiments. The DzyaloshinskMoriya (DM) interaction and the magnetic anisotropy distribution of thin-film heterostructures, parameters that are critical in developing next-generation storage class magnetic memory technologies, are estimated from a magnetic domain image. Micromagnetic simulation is used to generate thousands of random images for training and model validation. A convolutional neural network system is employed as the learning tool. The DM exchange constant of typical Co-based thin-film heterostructures is studied using the trained system: the estimated values are in good agreement with experiments. Moreover, we show that the system can independently determine the magnetic anisotropy distribution, demonstrating the potential of pattern recognition. This approach can considerably simplify experimental processes and broaden the scope of materials research., 19H02553
01 Apr. 2019 - 31 Mar. 2022 - Spin-orbitronics and device application
ONO Teruo; KOHNO hiroshi; NAKATANI yoshinobu; NAGAHAMA taro; NAKAMURA kohji; HAYASHI masamitsu; CHIBA daichi; TANIYAMA tomoyasu
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Specially Promoted Research, Kyoto University, Grant-in-Aid for Specially Promoted Research, This project established the field of Spin-orbitronics by exploiting the spin-orbit interaction of electrons in solids to form new materials with novel functionalities and find new physics. New approach for designing strong magnetic anisotropy materials, novel way for efficient magnetization control, and new method for controlling spins in antiferromagnets were developed, which will enable development of high speed, energy efficient electronic devices and technological innovations., 15H05702
2015 - 2019 - Studies of the observation of magnetic skyrmions in ferromagnetic thin films
KEISUKE Yamada; NAKATANI Yoshinobu; ONO Teruo; YAMAGUCHI Akinobu; TANABE Kenji
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Gifu University, Grant-in-Aid for Challenging Exploratory Research, The observation of Skyrmion at room temperature were investigated using ferromagnetic thin films with perpendicular magnetic anisotropy. (1) In the experimental research using Co/Ni multilayer films, it observed the movement of the magnetic domain structures in magnetic wires, however it did not observed the Skyrmions. (2) In the research using numerical simulations, we investigated the nucleation and annihilation conditions of Skyrmions in Co / Ni multilayers and clarified the conditions that the Skyrmion exists stably at room temperature. As other research, we investigated that (3) the magnitude of the topological Hall effect depending on the magnetization structure in the cross-shaped magnetic wire, and that (4) the changing the magnetic domain structures in the Ni wire on the piezoelectric substrate LiNbO3., 15K13272
01 Apr. 2015 - 31 Mar. 2018 - Simulation analysys of the domain wall motion by spin current
Nakatani Yoshinobu
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C), The University of Electro-Communications, Grant-in-Aid for Scientific Research (C), Recently a storage system, which uses a magnetic domain wall as an information carrier was proposed, and the domain wall have been studied intensively. Because the domain wall motion velocity is related to the operation speed of the storage system, it is required to obtain the conditions for fast domain wall motion, and to investigate the domain wall motion mechanism. In this research, the effect of the Dzyaroshinskii-Moriya interaction on the domain wall motion induced by a spin current, a magnetic field, and an electric field were investigated by computer simulation, and obtained the conditions for fast domain wall motion, and revealed the domain wall motion mechanism., 26390008
01 Apr. 2014 - 31 Mar. 2017 - Development of Novel Spin Dynamics Devices
Ono Teruo; MORIYAMA Takahiro; KIM KabJin; CHIBA Daich; KOHNO Hiroshi; NAKATANI Yoshinobu
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (S), Kyoto University, Grant-in-Aid for Scientific Research (S), The purpose of this project is to develop novel spin devices that utilize the current-induced spin dynamics in non-uniform spin structure, such as a magnetic domain wall and a magnetic vortex. We succeeded in demonstrating the operation of the spin devices such as domain wall memory and vortex core memory. Furthermore, we obtained unexpected results such as the observation of spin motive force in gyrating vortex core and the modulation of ferromagnetic transition temperature of Cobalt by electric field gating., 23221008
31 May 2011 - 31 Mar. 2016 - Control of spin currents and functions
TANAKA Masaaki; SUZUKI Yoshishige; SHIMIZU Hiromasa; NAKATANI Yoshinobu
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research on Priority Areas, The University of Tokyo, Grant-in-Aid for Scientific Research on Priority Areas, This research members are the leaders of each group in A05 "Functions and Control of Spin Currents". We explored principles of control and transformations of various signals and their functions, and proposed new devices and realized their operations. Cooperating with other groups, we studied spin-polarized-current-controlled devices, spin current, microwave and thermal devices, optical spintronics devices, spin-current-induced magnetization reversal devices, and theories and designs. Furthermore, we enhanced exchange of ideas and collaborations. We organized the 6th International Conference on Physics and Applications of Spin Related Phenomena in Semiconductors (PASPS-VI)) in Tokyo, August 2010 (Conference chair : Masaaki Tanaka), and contributed the worldwide advance of this field., 19048019
2007 - 2010 - Computer simulation of magnetic vortex core switching by spin current
NAKATANI Yoshinobu
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research on Priority Areas, The University of Electro-Communications, Grant-in-Aid for Scientific Research on Priority Areas, Recently, there are many works relating to the vortex core dynamics by spin current. In this research the mechanism of the vortex core rotation and switching by spin current are investigated by using computer simulation. We also investigate the conditions to use this mechanism for magnetic devices. Because these simulation requires huge amount of the computation time, we propose the method to accelerate the calculation speed by using the graphic processing unit., 19048021
2007 - 2010 - ブロッホライン対書き込み操作のシミュレーション
仲谷 栄伸
日本学術振興会, 科学研究費助成事業 奨励研究(A), 電気通信大学, 奨励研究(A), 磁性薄膜中に存在する磁壁上の磁化構造であるブロッホラインを情報の記憶単位として用いるブロッホライン記憶装置は、次世代の不揮発性高密度個体記憶装置として現在研究が進められている。情報の書き込み操作であるブロッホライン対の書き込みの操作の一つとして、ブロッホポイント注入法が提案されている。この手法ではまずunwindingな二つのブロッホライン対を生成し、それぞれの内側のブロッホラインを消去することで、windingで安定なブロッホライン対を生成する。内側のブロッホラインの消去過程において、ブロッホポイントの発生が仮定されているが、実験ではブロッホポイントは直接観測することは出来ない。ここでは計算機シミュレーションを行なうことで、ブロッホライン書き込み操作の一部であるブロッホポイントの注入によるブロッホライン対の消滅過程の詳細を求めた。これらの計算は東京大学大型計算機センターのスーパーコンピュータを用いて行なった。計算は三次元の動的計算であるために、その結果として膨大な数値データが得られるが、これを詳細に解析するためには数値の視覚化が必要になる。この作業は研究室のワークステーション上で行なった。数値データと視覚化した画像データは膨大な量になるために、専用のハードディスク装置を購入した。, 05750285
1993 - 1994
