博士（工学）, 東京大学

Portable ultrahigh magnetic fields PINK

XFEL

FBG

磁歪

超強磁場

Correlated electron system with multiple orbitals

Exciton condensation

Natural sciences, Magnetism, superconductivity, and strongly correlated systems

Dec. 2024 - Present
The University of Electro-Communications, 基盤理工学専攻, 准教授

Nov. 2021 - Nov. 2024
The University of Electro-Communications, Department of Engineering Science, Research Associate

Apr. 2013 - Oct. 2021
University of Tokyo, The Institute for Solid State Physics, Research Associate

Apr. 2008 - Mar. 2013
University of Tokyo, Graduate School of Engineering, Department of Applied Physics

Apr. 2006 - Mar. 2008
University of Tokyo, School of Engineering, Department of Mechanical Engineering

Apr. 2004 - Mar. 2006
University of Tokyo, College of Arts and Sciences, Natural Science 1

Apr. 2019 - Mar. 2020
領域3運営委員, 日本物理学会, Society

Apr. 2018 - Mar. 2019
教育委員, 日本真空学会, Society

Apr. 2013 - Mar. 2018
編集員, 日本真空学会, Society

Apr. 2025
文部科学省
超100テスラ強磁場におけるスピン格子相互作用の研究
令和７年度 科学技術分野の文部科学大臣表彰 若手科学者賞, 池田暁彦

Mar. 2024
Japanese Physical Society of Japan
Discovery of novel electronic phases in LaCoO3 by developing novel strain gauge used at 1000 T
Young Scientist Award of the Physical Society of Japan (Strongly correlated electron systems), Akihiko Ikeda

Nov. 2018
エヌエフ基金
独自開発超高速ひずみ計測装置による極限強磁場中スピン格子科学の開拓
第7回研究開発奨励賞（先端計測）, Akihiko Ikeda

Mar. 2018
Institute for Solid State Physics
「100テスラ領域における新奇スピン状態秩序相の発見と磁歪計測装置の開発」
ISSP Young Scientist Medal, Akihiko Ikeda

Nov. 2017
High magneitc field forum
「メガガウス超強磁場における新奇スピン状態秩序相の発見」
Miura award for young scientist, Akihiko Ikeda

Jun. 2016
Physical Review B
Editors' Suggestion, 池田暁彦

Nov. 2012
第8回放射光表面科学研究部会・顕微ナノ材料科学研究会
Nuclear resonant scattering from physisorbed 83Kr mono-layer
最優秀ポスター賞, Akihiko Ikeda

Nov. 2012
JASRI
「物理吸着クリプトン単原子層のメスバウアー分光：表面電場勾配のプローブとして」
The 5th SPring-8 Budding Researchers Award, Akihiko Ikeda

Dec. 2011
日本表面科学会
「Au(001)上のXe単層・多層吸着層からのレーザー誘起昇脱離：飛行時間分布の層数依存性」
講演奨励賞 スチューデント部門, 池田暁彦

Experimental and Numerical Studies of the Collapse of Dense Clouds Induced by Herbig-Haro Stellar Jets
Marin Fontaine; Clotilde Busschaert; Yaniss Benkadoum; Isabeau A. Bertrix; Michel Koenig; Frederic Lefevre; Jean-Raphael Marques; Diego Oportus; Akihiko Ikeda; Yasuhiro H. Matsuda; Emeric Falize; Bruno Albertazzi
ASTROPHYSICAL JOURNAL, 981, 2, 10 Mar. 2025, Peer-reviwed
Scientific journal, English

A Review on Magnetic Field Induced Spin Crossover in LaCoO3 up to 600 T
Akihiko Ikeda; Yasuhiro H. Matsuda; Keisuke Sato; Joji Nasu
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, 93, 12, 15 Dec. 2024, Peer-reviwed
Scientific journal, English

Crystal field magnetostriction of spin ice under ultrahigh magnetic fields
Nan Tang; Masaki Gen; Martin Rotter; Huiyuan Man; Kazuyuki Matsuhira; Akira Matsuo; Koichi Kindo; Akihiko Ikeda; Yasuhiro H. Matsuda; Philipp Gegenwart; Satoru Nakatsuji; Yoshimitsu Kohama
Physical Review B, American Physical Society (APS), 110, 21, 09 Dec. 2024, Peer-reviwed
Scientific journal

A concise 40 T pulse magnet for condensed matter experiments
Akihiko Ikeda; Kosuke Noda; Kotomi Shimbori; Kenta Seki; Dilip Bhoi; Azumi Ishita; Jin Nakamura; Kazuyuki Matsubayashi; Kazuto Akiba
Journal of Applied Physics, AIP Publishing, 136, 17, 04 Nov. 2024, Peer-reviwed, There is a growing interest in using pulsed high magnetic field as a controlling parameter of physical phenomena in various scientific disciplines, such as condensed matter physics, particle physics, plasma physics, chemistry, and biological studies. We devised a concise and portable pulsed magnetic field generator that produces a 40 T field with a pulse duration of 2 ms. It is assembled using only off-the-shelf components and a homemade coil that leverages small computers, Raspberry Pi, and Python codes. It allows for straightforward modification for general purposes. As working examples, we show representative applications in condensed matter experiments of magnetoresistance, magnetization, and magnetostriction measurements for graphite, NdNi2P2, and NdCo2P2, respectively, with the maximum magnetic field of 41 T and the lowest temperature of 4.2 K.
Scientific journal

Breathing pyrochlore magnet CuGaCr4S8 : Magnetic, thermodynamic, and dielectric properties
Masaki Gen; Hajime Ishikawa; Atsushi Miyake; Takeshi Yajima; Harald O. Jeschke; Hajime Sagayama; Akihiko Ikeda; Yasuhiro H. Matsuda; Koichi Kindo; Masashi Tokunaga; Yoshimitsu Kohama; Takashi Kurumaji; Yusuke Tokunaga; Taka-hisa Arima
Physical Review Materials, American Physical Society (APS), 7, 10, 16 Oct. 2023, Peer-reviwed
Scientific journal

Signatures of a magnetic superstructure phase induced by ultrahigh magnetic fields in a breathing pyrochlore antiferromagnet
Masaki Gen; Akihiko Ikeda; Kazushi Aoyama; Harald O. Jeschke; Yuto Ishii; Hajime Ishikawa; Takeshi Yajima; Yoshihiko Okamoto; Xuguang Zhou; Daisuke Nakamura; Shojiro Takeyama; Koichi Kindo; Yasuhiro H. Matsuda; Yoshimitsu Kohama
Proceedings of the National Academy of Sciences, Proceedings of the National Academy of Sciences, 120, 33, 07 Aug. 2023, Peer-reviwed, The mutual coupling of spin and lattice degrees of freedom is ubiquitous in magnetic materials and potentially creates exotic magnetic states in response to the external magnetic field. Particularly, geometrically frustrated magnets serve as a fertile playground for realizing magnetic superstructure phases. Here, we observe an unconventional two-step magnetostructural transition prior to a half-magnetization plateau in a breathing pyrochlore chromium spinel by means of state-of-the-art magnetization and magnetostriction measurements in ultrahigh magnetic fields available up to 600 T. Considering a microscopic magnetoelastic theory, the intermediate-field phase can be assigned to a magnetic superstructure with a three-dimensional periodic array of 3-up-1-down and canted 2-up-2-down spin molecules. We attribute the emergence of the magnetic superstructure to a unique combination of the strong spin–lattice coupling and large breathing anisotropy.
Scientific journal

Gradual Charge Order Melting in Bi0.5Ca0.5MnO3 Induced by Ultrahigh Magnetic Fields
Yuto Ishii; Akihiko Ikeda; Masashi Tokunaga; Koichi Kindo; Akira Matsuo; Yasuhiro H. Matsuda
Journal of the Physical Society of Japan, Physical Society of Japan, 92, 7, 074702, 15 Jul. 2023, Peer-reviwed
Scientific journal

Unveiling new quantum phases in the Shastry-Sutherland compound SrCu2(BO3)2 up to the saturation magnetic field
T. Nomura; P. Corboz; A. Miyata; S. Zherlitsyn; Y. Ishii; Y. Kohama; Y. H. Matsuda; A. Ikeda; C. Zhong; H. Kageyama; F. Mila
Nature Communications, Springer Science and Business Media LLC, 14, 1, 24 Jun. 2023, Peer-reviwed, Abstract

Under magnetic fields, quantum magnets often undergo exotic phase transitions with various kinds of order. The discovery of a sequence of fractional magnetization plateaus in the Shastry-Sutherland compound SrCu₂(BO₃)₂ has played a central role in the high-field research on quantum materials, but so far this system could only be probed up to half the saturation value of the magnetization. Here, we report the first experimental and theoretical investigation of this compound up to the saturation magnetic field of 140 T and beyond. Using ultrasound and magnetostriction techniques combined with extensive tensor-network calculations (iPEPS), several spin-supersolid phases are revealed between the 1/2 plateau and saturation (1/1 plateau). Quite remarkably, the sound velocity of the 1/2 plateau exhibits a drastic decrease of -50%, related to the tetragonal-to-orthorhombic instability of the checkerboard-type magnon crystal. The unveiled nature of this paradigmatic quantum system is a new milestone for exploring exotic quantum states of matter emerging in extreme conditions.
Scientific journal

Magnetic-field-induced valence change in Eu ( Co_1−x_Ni_x )_2_P_2_ up to 60 T
Raito Nakamura; Azumi Ishita; Jin Nakamura; Hiroto Ohta; Yuya Haraguchi; Hiroko Aruga Katori; Hajime Ishikawa; Akira Matsuo; Koichi Kindo; Minoru Nohara; Akihiko Ikeda
Last, Physical Review B, American Physical Society (APS), 107, 23, 235110, 05 Jun. 2023, Peer-reviwed
Scientific journal

Single crystal growths and magnetic properties of hexagonal polar semimetals RAuGe (R = Y, Gd–Tm, and Lu)
Takashi Kurumaji; Masaki Gen; Shunsuke Kitou; Kazuhiko Ikeuchi; Mitsutaka Nakamura; Akihiko Ikeda; Taka-hisa Arima
Journal of Alloys and Compounds, Elsevier BV, 947, 169475-169475, Jun. 2023, Peer-reviwed
Scientific journal

Signature of spin-triplet exciton condensations in LaCoO3 at ultrahigh magnetic fields up to 600 T.
Akihiko Ikeda; Yasuhiro H Matsuda; Keisuke Sato; Yuto Ishii; Hironobu Sawabe; Daisuke Nakamura; Shojiro Takeyama; Joji Nasu
Lead, Nature communications, 14, 1, 1744-1744, 04 Apr. 2023, Peer-reviwed, True, Bose-Einstein condensation of electron-hole pairs, exciton condensation, has been effortfully investigated since predicted 60 years ago. Irrefutable evidence has still been lacking due to experimental difficulties in verifying the condensation of the charge neutral and non-magnetic spin-singlet excitons. Whilst, condensation of spin-triplet excitons is a promising frontier because spin supercurrent and spin-Seebeck effects will be observable. A canonical cobaltite LaCoO3 under very high magnetic fields is a propitious candidate, yet to be verified. Here, we unveil the exotic phase diagram of LaCoO3 up to 600 T generated using the electromagnetic flux compression method and the state-of-the-art magnetostriction gauge. We found the continuous magnetostriction curves and a bending structure, which suggest the emergence of two distinct spin-triplet exciton condensates. By constructing a phenomenological model, we showed that quantum fluctuations of excitons are crucial for the field-induced successive transitions. The spin-triplet exciton condensation in a cobaltite, which is three-dimensional and thermally equilibrated, opens up a novel venue for spintronics technologies with spin-supercurrent such as a spin Josephson junction.
Scientific journal, English

Double dome structure of the Bose–Einstein condensation in diluted S = 3/2 quantum magnets
Yoshito Watanabe; Atsushi Miyake; Masaki Gen; Yuta Mizukami; Kenichiro Hashimoto; Takasada Shibauchi; Akihiko Ikeda; Masashi Tokunaga; Takashi Kurumaji; Yusuke Tokunaga; Taka-hisa Arima
Nature Communications, Springer Science and Business Media LLC, 14, 1, 10 Mar. 2023, Peer-reviwed, Abstract

Bose–Einstein condensation (BEC) in quantum magnets, where bosonic spin excitations condense into ordered ground states, is a realization of BEC in a thermodynamic limit. Although previous magnetic BEC studies have focused on magnets with small spins of S ≤ 1, larger spin systems potentially possess richer physics because of the multiple excitations on a single site level. Here, we show the evolution of the magnetic phase diagram of S = 3/2 quantum magnet Ba₂CoGe₂O₇ when the averaged interaction J is controlled by a dilution of magnetic sites. By partial substitution of Co with nonmagnetic Zn, the magnetic order dome transforms into a double dome structure, which can be explained by three kinds of magnetic BECs with distinct excitations. Furthermore, we show the importance of the randomness effects induced by the quenched disorder: we discuss the relevance of geometrical percolation and Bose/Mott glass physics near the BEC quantum critical point.
Scientific journal

Rhombic skyrmion lattice coupled with orthorhombic structural distortion in EuAl4
Masaki Gen; Rina Takagi; Yoshito Watanabe; Shunsuke Kitou; Hajime Sagayama; Naofumi Matsuyama; Yoshimitsu Kohama; Akihiko Ikeda; Yoshichika Ōnuki; Takashi Kurumaji; Taka-hisa Arima; Shinichiro Seki
Physical Review B, American Physical Society (APS), 107, 2, 25 Jan. 2023, Peer-reviwed
Scientific journal

Magnetic-Field-Induced Insulator Metal Transition of W-doped VO2 Observed by Electromagnetic Flux Compression at ISSP
Yasuhiro H. Matsuda; Yuji Muraoka; Daisuke Nakamura; Akihiko Ikeda; Yuto Ishii; Xu-Guang Zhou; Hironobu Sawabe; Shojiro Takeyama
J. Phys. Soc. Jpn., 91, 10, 101008, 15 Oct. 2022, Peer-reviwed
Scientific journal, English

Anisotropic magnetotransport properties coupled with spiral spin modulation in a magnetic semimetal EuZnGe
Takashi Kurumaji; Masaki Gen; Shunsuke Kitou; Hajime Sagayama; Akihiko Ikeda; Taka-hisa Arima
Physical Review Materials, American Physical Society (APS), 6, 9, 22 Sep. 2022, Peer-reviwed
Scientific journal

Complex magnetic phase diagram with a small phase pocket in a three-dimensional frustrated magnet CuInCr4S8
M. Gen; H. Ishikawa; A. Ikeda; A. Miyake; Z. Yang; Y. Okamoto; M. Mori; K. Takenaka; H. Sagayama; T. Kurumaji; Y. Tokunaga; T. Arima; M. Tokunaga; K. Kindo; Y. H. Matsuda; Y. Kohama
Physical Review Research, American Physical Society (APS), 4, 3, 25 Aug. 2022, Peer-reviwed
Scientific journal

Metastable magnetization plateaus in the S=1 organic spin ladder BIP-TENO induced by a microsecond-pulsed megagauss field
Kazuya Nomura; Yasuhiro H. Matsuda; Akihiko Ikeda; Yoshimitsu Kohama; Hiroshi Tsuda; Naoki Amaya; Toshio Ono; Yuko Hosokoshi
Physical Review B, American Physical Society (APS), 105, 21, 23 Jun. 2022, Peer-reviwed
Scientific journal

Magnetovolume Effect on the First-Order Metamagnetic Transition in UTe₂
Atsushi Miyake; Masaki Gen; Akihiko Ikeda; Kazumasa Miyake; Yusei Shimizu; Yoshiki J. Sato; Dexin Li; Ai Nakamura; Yoshiya Homma; Fuminori Honda; Jacques Flouquet; Masashi Tokunaga; Dai Aoki
Journal of the Physical Society of Japan, Physical Society of Japan, 91, 6, 15 Jun. 2022, Peer-reviwed
Scientific journal

Enhancement of giant magnetoelectric effect in Ni-doped CaBaCo4O7
M. Gen; A. Miyake; H. Yagiuchi; Y. Watanabe; A. Ikeda; Y. H. Matsuda; M. Tokunaga; T. Arima; Y. Tokunaga
Physical Review B, American Physical Society (APS), 105, 21, 09 Jun. 2022, Peer-reviwed
Scientific journal

Closing the hybridization charge gap in the Kondo semiconductor SmB6 with an ultrahigh magnetic field
Daisuke Nakamura; Atsushi Miyake; Akihiko Ikeda; Masashi Tokunaga; Fumitoshi Iga; Yasuhiro H. Matsuda
Physical Review B, American Physical Society (APS), 105, 24, 06 Jun. 2022, Peer-reviwed
Scientific journal

Generating 77 T using a portable pulse magnet for single-shot quantum beam experiments
Akihiko Ikeda; Yasuhiro H. Matsuda; Xuguang Zhou; Shiyue Peng; Yuto Ishii; Takeshi Yajima; Yuya Kubota; Ichiro Inoue; Yuichi Inubushi; Kensuke Tono; Makina Yabashi
Lead, Applied Physics Letters, AIP Publishing, 120, 14, 142403-142403, 04 Apr. 2022, Peer-reviwed, We devised a portable system that generates pulsed high magnetic fields up to 77 T with 3 μs duration. The system employs the single turn coil method, a destructive way of field generation. The system consists of a capacitor of 10.4 μF, a 30 kV charger, a mono air-gap switch, a triggering system, and a magnet clamp, which weighs less than 1.0 tons in total and is transportable. The system offers opportunities for single-shot experiments at ultrahigh magnetic fields in combinations with novel quantum beams. The single-shot x-ray diffraction experiment using a x-ray free-electron laser at 65 T is presented. We comment on the possible update of the system for the generation of 100 T.
Scientific journal

Physical properties of liquid oxygen under ultrahigh magnetic fields
T. Nomura; A. Ikeda; M. Gen; A. Matsuo; K. Kindo; Y. Kohama; Y. H. Matsuda; S. Zherlitsyn; J. Wosnitza; H. Tsuda; T. C. Kobayashi
Physical Review B, American Physical Society (APS), 104, 22, 224423, 20 Dec. 2021, Peer-reviwed
Scientific journal

Phase transition in the 5d1 double perovskite Ba2CaReO6 induced by high magnetic field
Hajime Ishikawa; Daigorou Hirai; Akihiko Ikeda; Masaki Gen; Takeshi Yajima; Akira Matsuo; Yasuhiro H. Matsuda; Zenji Hiroi; Koichi Kindo
Physical Review B, 104, 17, 174422, 18 Nov. 2021, Peer-reviwed
Scientific journal, English

Magnetoconduction in the Correlated Semiconductor FeSi in Ultrastrong Magnetic Fields up to a Semiconductor-to-Metal Transition
D. Nakamura; Y. H. Matsuda; A. Ikeda; A. Miyake; M. Tokunaga; S. Takeyama; T. Kanomata
Physical Review Letters, American Physical Society (APS), 127, 15, 06 Oct. 2021, Peer-reviwed
Scientific journal

Field-induced valence fluctuations in YbB12
R. Kurihara; A. Miyake; M. Tokunaga; A. Ikeda; Y. H. Matsuda; A. Miyata; D. I. Gorbunov; T. Nomura; S. Zherlitsyn; J. Wosnitza; F. Iga
Physical Review B, American Physical Society (APS), 103, 11, 03 Mar. 2021, Peer-reviwed
Scientific journal

Higher magnetic-field generation by a mass-loaded single-turn coil
M. Gen; A. Ikeda; S. Kawachi; T. Shitaokoshi; Y. H. Matsuda; Y. Kohama; T. Nomura
Review of Scientific Instruments, AIP Publishing, 92, 3, 033902-033902, 01 Mar. 2021, Peer-reviwed
Scientific journal

Particle-Hole Symmetry Breaking in a Spin-Dimer System TlCuCl3 Observed at 100 T
X.-G. Zhou; Yuan Yao; Y. H. Matsuda; A. Ikeda; A. Matsuo; K. Kindo; H. Tanaka
Physical Review Letters, American Physical Society (APS), 125, 26, 31 Dec. 2020, Peer-reviwed
Scientific journal

Single shot x-ray diffractometry in SACLA with pulsed magnetic fields up to 16 T
Akihiko Ikeda; Yasuhiro H. Matsuda; Xuguang Zhou; Takeshi Yajima; Yuya Kubota; Kensuke Tono; Makina Yabashi
Lead, PHYSICAL REVIEW RESEARCH, 2, 4, Nov. 2020, Peer-reviwed
Scientific journal, English

Two Spin-State Crystallizations in LaCoO3
Akihiko Ikeda; Yasuhiro H. Matsuda; Keisuke Sato
Lead, PHYSICAL REVIEW LETTERS, 125, 17, Oct. 2020, Peer-reviwed
Scientific journal, English

Magnetic-field-induced insulator-metal transition in W-doped VO2 at 500 T
Yasuhiro H. Matsuda; Daisuke Nakamura; Akihiko Ikeda; Shojiro Takeyama; Yuki Suga; Hayato Nakahara; Yuji Muraoka
NATURE COMMUNICATIONS, 11, 1, Jul. 2020, Peer-reviwed
Scientific journal, English

Direct measurement of resistivity in destructive pulsed magnetic fields
Yoshimitsu Kohama; Fuyuki Nabeshima; Atsutaka Maeda; Akihiko Ikeda; Yasuhiro H. Matsuda
REVIEW OF SCIENTIFIC INSTRUMENTS, 91, 3, 033901-033901, Mar. 2020, Peer-reviwed, True
Scientific journal, English

High magnetic field x-ray diffraction study of the alpha phase of solid oxygen: Absence of giant magnetostriction
Yasuhiro H. Matsuda; Ayumi Shimizu; Akihiko Ikeda; Toshihiro Nomura; Takeshi Yajima; Toshiya Inami; Kohki Takahashi; Tatsuo C. Kobayashi
PHYSICAL REVIEW B, 100, 21, Dec. 2019, Peer-reviwed
Scientific journal, English

Magnetoelastic couplings in the deformed kagome quantum spin lattice of volborthite
Akihiko Ikeda; Shunsuke Furukawa; Oleg Janson; Yasuhiro H. Matsuda; Shojiro Takeyama; Takeshi Yajima; Zenji Hiroi; Hajime Ishikawa
PHYSICAL REVIEW B, 99, 14, Apr. 2019, Peer-reviwed
Scientific journal, English

Laboratory Guide : Development of high-speed 100 MHz strain monitor based on fiber Bragg grating technique and observation of spin-lattice couplings at ultrahigh magnetic fields
池田 暁彦; 松田 康弘
Lead, 固体物理, アグネ技術センター, 54, 3, 147-157, Mar. 2019, Peer-reviwed
Japanese

Record indoor magnetic field of 1200 T generated by electromagnetic flux-compression
Nakamura D; Ikeda A; Sawabe H; Matsuda Y. H; Takeyama S
REVIEW OF SCIENTIFIC INSTRUMENTS, 89, 9, Sep. 2018, Peer-reviwed

Note: Optical filter method for high-resolution magnetostriction measurement using fiber Bragg grating under millisecond-pulsed high magnetic fields at cryogenic temperatures
Akihiko Ikeda; Yasuhiro H. Matsuda; Hiroshi Tsuda
REVIEW OF SCIENTIFIC INSTRUMENTS, 89, 9, Sep. 2018, Peer-reviwed
Scientific journal, English

Magnetic-Field-Induced Kondo Metal Realized in YbB12
Taku T. Terashima; Yasuhiro H. Matsuda; Yoshimitsu Kohama; Akihiko Ikeda; Akihiro Kondo; Koichi Kindo; Fumitoshi Iga
PHYSICAL REVIEW LETTERS, 120, 25, 257206-257206, Jun. 2018, Peer-reviwed, True
Scientific journal, English

100 MHz high-speed strain monitor using fiber Bragg grating and optical filter applied for magnetostriction measurements of cobaltite at magnetic fields beyond 100 T
Akihiko Ikeda; Toshihiro Nomura; Yasuhiro H. Matsuda; Shuntaro Tani; Yohei Kobayashi; Hiroshi Watanabe; Keisuke Sato
PHYSICA B-CONDENSED MATTER, 536, 847-849, May 2018, Peer-reviwed
Scientific journal, English

Crossroad : Shrinking a Coin Using Pulsed High Magnetic Fields
池田 暁彦; 松田 康弘
日本物理学会誌 = Butsuri, 日本物理学会, 73, 5, 318-320, May 2018
Japanese

Magnetostriction studies up to megagauss fields using fiber Bragg grating technique
Akihiko Ikeda; Yasuhiro H. Matsuda; Daisuke Nakamura; Shojiro Takeyama; Hiroshi Tsuda; Kazuya Nomura; Ayumi Shimizu; Akira Matsuo; Toshihiro Nomura; Tatsuo C. Kobayashi; Takeshi Yajima; Hajime Ishikawa; Zenji Hiroi; Masahiko Isobe; Touru Yamauchi; Keisuke Sato
2018 16TH INTERNATIONAL CONFERENCE ON MEGAGAUSS MAGNETIC FIELD GENERATION AND RELATED TOPICS (MEGAGAUSS), 98-106, 2018, Peer-reviwed
International conference proceedings, English

Megagauss-field effect on the metal-insulator transition in V(1-x)WxO(2) (x=0.06)
Yasuhiro H. Matsuda; Daisuke Nakamura; Akihiko Ikeda; Shojiro Takeyama; Yuji Muraoka; Yuki Suga
2018 16TH INTERNATIONAL CONFERENCE ON MEGAGAUSS MAGNETIC FIELD GENERATION AND RELATED TOPICS (MEGAGAUSS), 107-110, 2018, Peer-reviwed
International conference proceedings, English

Spin-lattice separation of the spin-ladder compound BIP-TENO by microsecond megagauss field
Kazuya Nomura; Akihiko Ikeda; Yoshimitsu Kohama; Yasuhiro H. Matsuda; Shojiro Takeyama; Naoki Amaya; Toshio Ono; Yuko Hosokoshi
2018 16TH INTERNATIONAL CONFERENCE ON MEGAGAUSS MAGNETIC FIELD GENERATION AND RELATED TOPICS (MEGAGAUSS), 150-153, 2018, Peer-reviwed
International conference proceedings, English

1000 T project of the electro-magnetic flux compression at Kashiwa, UTokyo
Shojiro Takeyama; Daisuke Nakamura; Akihiko Ikeda; Hironobu Sawabe; Yasuhiro H. Matsuda
2018 16TH INTERNATIONAL CONFERENCE ON MEGAGAUSS MAGNETIC FIELD GENERATION AND RELATED TOPICS (MEGAGAUSS), 1-4, 2018, Peer-reviwed
International conference proceedings, English

Contactless ultra-high frequency AC-conductivity measurement applicable to destructive magnets above 100 T
Daisuke Nakamura; Akihiko Ikeda; Yasuhiro H. Matsuda; Shojiro Takeyama
2018 16TH INTERNATIONAL CONFERENCE ON MEGAGAUSS MAGNETIC FIELD GENERATION AND RELATED TOPICS (MEGAGAUSS), 45-48, 2018, Peer-reviwed
International conference proceedings, English

High-speed 100 MHz strain monitor using fiber Bragg grating and optical filter for magnetostriction measurements under ultrahigh magnetic fields
Akihiko Ikeda; Toshihiro Nomura; Yasuhiro H. Matsuda; Shuntaro Tani; Yohei Kobayashi; Hiroshi Watanabe; Keisuke Sato
REVIEW OF SCIENTIFIC INSTRUMENTS, 88, 8, Aug. 2017, Peer-reviwed
Scientific journal, English

Novel spin-crossover in strongly correlated cobaltite
池田 暁彦; 松田 康弘; 佐藤 桂輔
固体物理, アグネ技術センター, 52, 6, 335-348, Jun. 2017
Japanese

Magnetization Process of the Kondo Insulator YbB12 in Ultrahigh Magnetic Fields
Taku T. Terashima; Akihiko Ikeda; Yasuhiro H. Matsuda; Akihiro Kondo; Koichi Kindo; Fumitoshi Iga
JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN, 86, 5, May 2017, Peer-reviwed
Scientific journal, English

Magnetic-field-induced spin crossover of Y-doped Pr0.7Ca0.3CoO3
Akihiko Ikeda; Suyeon Lee; Taku T. Terashima; Yasuhiro H. Matsuda; Masashi Tokunaga; Tomoyuki Naito
PHYSICAL REVIEW B, 94, 11, Sep. 2016, Peer-reviwed
Scientific journal, English

Spin state ordering of strongly correlating LaCoO3 induced at ultrahigh magnetic fields
Akihiko Ikeda; Toshihiro Nomura; Yasuhiro H. Matsuda; Akira Matsuo; Koichi Kindo; Keisuke Sato
PHYSICAL REVIEW B, 93, 22, Jun. 2016, Peer-reviwed
Scientific journal, English

One-Way Transparency of Light in Multiferroic CuB2O4
S. Toyoda; N. Abe; S. Kimura; Y. H. Matsuda; T. Nomura; A. Ikeda; S. Takeyama; T. Arima
PHYSICAL REVIEW LETTERS, 115, 26, Dec. 2015, Peer-reviwed
Scientific journal, English

Nuclear resonant scattering of synchrotron radiation by physisorbed Kr on TiO2(110) surfaces in multilayer and monolayer regimes
Akihiko Ikeda; Taizo Kawauchi; Tatsuo Okano; Katsuyuki Fukutani; Masuaki Matsumoto; Xiao Wei Zhang; Yoshitaka Yoda
PHYSICAL REVIEW B, 91, 15, Apr. 2015, Peer-reviwed
Scientific journal, English

Photon stimulated desorption of and nuclear resonant scattering by noble gas atoms at solid surfaces
Akihiko Ikeda
18 Jan. 2015, When a noble gas atom approaches a solid surface, it is adsorbed via the Van

der Waals force, which is called physisorption. In this thesis, several

experimental results concerning physisorbed atoms at surfaces are presented.

First, photon stimulated desorption of Xe atoms from a Au substrate using

nano-second laser is presented. With the time-of-flight measurements, the

translational temperature and the desorption yield of desorbing Xe as a

function of laser fluence are obtained. It is discovered that there are

non-thermal and thermal desorption pathways. It is discussed that the former

path involves a transient formation of the negative ion of Xe. The desorption

flux dependence of the thermal pathway is also investigated. We found that at a

large desorption fluxes the desorption flow is thermalized due to the

post-desorption collisions. The resultant velocity and the temperature of the

flow is found to be in good agreement with the theoretical predictions based on

the Knudsen layer formation. Lastly, nuclear resonant scattering of synchrotron

radiation by the multi- and mono-layer of $^{83}$Kr at a surface of the

titanium oxide is presented. The use of the noble gas atoms as the probes of

the electric field gradient at the solid surfaces is discussed.

Knudsen layer formation in laser induced thermal desorption
Akihiko Ikeda; Masuaki Matsumoto; Shohei Ogura; Tatsuo Okano; Katsuyuki Fukutani
JOURNAL OF CHEMICAL PHYSICS, 138, 12, Mar. 2013, Peer-reviwed
Scientific journal, English

Photostimulated desorption of Xe from Au(001) surfaces via transient Xe- formation
Akihiko Ikeda; Masuaki Matsumoto; Shohei Ogura; Katsuyuki Fukutani; Tatsuo Okano
PHYSICAL REVIEW B, 84, 15, Oct. 2011, Peer-reviwed
Scientific journal, English

Magnetoelastic study on the itinerant helimagnet SrFeO₃ and reconsideration of the phase diagram
厳正輝; 今城周作; 鬼頭俊介; 徳永祐介; 新居陽一; 池田暁彦; 小濱芳允; 金道浩一; 石渡晋太郎; 有馬孝尚; 有馬孝尚
2024, 日本物理学会講演概要集(CD-ROM), 79, 1, 2189-079X, 202402226333678116

Single crystal growths and physical properties of magnetic polar semimetals RTX (R=Y, Gd-Tm, Lu)
車地崇; 厳正輝; 厳正輝; 鬼頭俊介; 池内和彦; 中村充孝; 池田暁彦; 有馬孝尚; 有馬孝尚
2023, 日本物理学会講演概要集(CD-ROM), 78, 1, 2189-079X, 202302233537255485

Single crystal growth and anisotropic magnetotransport properties of a triangular-lattice helimagnet EuZnGe
車地崇; 厳正輝; 厳正輝; 鬼頭俊介; 佐賀山基; 池田暁彦; 有馬孝尚; 有馬孝尚
2022, 日本物理学会講演概要集(CD-ROM), 77, 2, 2189-079X, 202302233488411757

20pPSB-37 Temperature dependence of the magnetization of Kondo semiconductor YbB_<12> and the gap structure
Terashima T. T.; Ikeda A.; Matsuda Y. H.; Takeyama S.; Kondo A.; Kindo K.; Iga F.
The Physical Society of Japan (JPS), 2016, Meeting Abstracts of the Physical Society of Japan, 71, 2140-2140, Japanese, 2189-079X, 110010058095, AA12721570

22aPS-24 Magnetization measurements of valence fluctuating system EuNi_2X_2 (X = Si_<1-x>Ge_x, P) in ultra-high magnetic field over 100 T
Ichikawa T.; Ikeda A.; Matsuda Y. H.; Mitsuda A.; Wada H.
The Physical Society of Japan (JPS), 2016, Meeting Abstracts of the Physical Society of Japan, 71, 2418-2418, Japanese, 2189-079X, 110010058357, AA12721570

19pBM-9 Spin state ordering in LaCoO_3 above 100 T
Ikeda A.; Nomura T.; Matsuda Y. H.; Matsuo A.; Kindo K.; Sato K.
The Physical Society of Japan (JPS), 2016, Meeting Abstracts of the Physical Society of Japan, 71, 2027-2027, Japanese, 2189-079X, 110010057992, AA12721570

19pDC-4 Temperature dependence of the high-_eld induced spin-state transitions in (Pr_<1-y>Y_y)_<0:7>Ca_<0:3>CoO_3 (y=0:075; 0:1)
Ikeda A.; Lee S.; Matsuda Y. H.; Takeyama S.; Kindo K.; Naito T.
The Physical Society of Japan (JPS), 2015, Meeting Abstracts of the Physical Society of Japan, 70, 2209-2209, Japanese, 2189-079X, 110010029803, AA12721570

18aDA-10 Saturation behavior of magnetization of Kondo semiconductor YbB_<12> at high magnetic fields beyond 100 T
Terashima T. T.; Ikeda A.; Matsuda Y. H.; Takeyama S.; Kondo A.; Kindo K.; Iga F.
The Physical Society of Japan (JPS), 2015, Meeting Abstracts of the Physical Society of Japan, 70, 1984-1984, Japanese, 2189-079X, 110010029582, AA12721570

Nuclear resonant scattering of synchrotron radiation by 83Kr on TiO2
Ikeda Akihiko; Kawauchi Taizo; Matsumoto Masuaki; Okano Tatsuo; Fukutani Katsuyuki; Zhang Xiao Wei; Yoda Yoshitaka
放射光の特性である波長可変性，集光性，高輝度を活かすことで，Kr表面吸着層を試料としたメスバウアー分光を行った．実験では超高真空中に担持したTiO2(001)基板を20Kまで冷却した．試料としてKrの単層・多層吸着層を作成した．SPring-8 BL09XUにて実験を行った．本実験で初めて，単層吸着層からの信号を0.1Hz程度で取得できることを示した．多層・単層でのスペクトル形状の相違を議論する．, The Surface Science Society of Japan, 2012, Abstract of annual meeting of the Surface Science of Japan, 32, 184-184, 130005456590

The Surface Science Society of Japan (eds) Compendium of Surface and Interface Analysis
Akihiko Ikeda; Katsuyuki Fukutani
Joint work, Photo-stimulated desorption (p487-p492), Springer, Feb. 2018

X-ray experiment beyond 100 T
池田暁彦
Invited oral presentation, English, SACLA Users' meeting 2025, Invited
03 Mar. 2025
03 Mar. 2025- 04 Mar. 2025

X-ray diffraction above 100 T
池田暁彦
Invited oral presentation, English, 14th Ringberg Workshop: Science with FELs, Invited
02 Feb. 2025
02 Feb. 2025- 05 Feb. 2025

超100テスラ強磁場におけるXFEL実験の開拓
池田暁彦
Invited oral presentation, Japanese, 第38回日本放射光学会年会・放射光科学合同シンポジウム, Invited
11 Jan. 2025
10 Jan. 2025- 12 Jan. 2025

ポータブル 100 テスラ発生装置 PINK-02 とX線自由電子レーザーを用いた100テスラX線実験の開拓
池田暁彦
Invited oral presentation, Japanese, 第18回 物性科学領域横断研究会, Invited
26 Nov. 2024
26 Nov. 2024- 27 Nov. 2024

A review on magnetic field induced spin crossover in LaCoO3 up to 600 T
池田暁彦
Invited oral presentation, English, 70 years of the Tanabe-Sugano diagram, Invited
12 Sep. 2024
10 Sep. 2024- 12 Sep. 2024

Road to x-ray science at 100 T
池田暁彦
Invited oral presentation, English, Magnetics and Optics Research International Symposium 2024 (MORIS2024), Invited
29 May 2024
28 May 2024- 31 May 2024

Novel phases of LaCoO3 at 600 T
Akihiko Ikeda
Invited oral presentation, English, 日本物理学会, Invited
20 Mar. 2024
18 Mar. 2024- 21 Mar. 2024

Road to XFEL experiments on condensed matters at above 100 Tesla
Akihiko Ikeda
Invited oral presentation, English, Japan Physical Society meeting, Invited
19 Mar. 2024
18 Mar. 2024- 21 Mar. 2024

Using mini-coil and mini-bank in plasma experiments, and the possibility of 100 T plasma experiment
Akihiko Ikeda
Invited oral presentation, English, Matter in Extreme Conditions for MAgneTized PLAsmas (MECMATPLA), Invited, Peer-reviewed
07 Feb. 2024
05 Feb. 2024- 09 Feb. 2024

Road to X-ray science at 100 T
Akihiko Ikeda
Invited oral presentation, English, Frontiers of Synchrotron and XFEL Research at High Magnetic Field (MagX), Invited
09 Nov. 2023
08 Nov. 2023- 10 Nov. 2023

Quest for the investigation of spin-lattice couplings of matter at ultrahigh magnetic fields up to 600 T
Akihiko Ikeda
Invited oral presentation, English, The 15th Asia Pacific Physics Conference (APPC15), Invited
25 Aug. 2022
21 Aug. 2022- 26 Aug. 2022

Spin triplet exciton condensations in LaCoO3 at ultrahigh magnetic fields up to 600 T
Akihiko Ikeda
Invited oral presentation, English, the 29th International Conference on Low Temperature Physics (LT29), Invited
18 Aug. 2022
18 Aug. 2022- 24 Aug. 2022

Investigation of quantum phenomena of materials at well above 100 T by means of next generation quantum beams
JST FOREST, Principal investigator
Apr. 2023 - Mar. 2030

Promotion of the 1000-Tesla science
松田 康弘; 大和田 謙二; 池田 暁彦; 徳永 将史; 木村 尚次郎; 稲田 聡明; 岡 隆史; 伏屋 雄紀; 那須 譲治; 富田 裕介; 笠松 秀輔
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, The University of Tokyo, Grant-in-Aid for Transformative Research Areas (A), 23H04859
01 Apr. 2023 - 31 Mar. 2028

Investigation of spin-lattice couplins in strongly correlated condensed matters at 1000 T
池田 暁彦; 野村 肇宏; 米澤 進吾; 野原 実; 大池 広志
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, The University of Electro-Communications, Grant-in-Aid for Transformative Research Areas (A), 23H04861
01 Apr. 2023 - 31 Mar. 2028

状態密度変化によるゼロヒステリスの巨大磁気熱量効果の実現に向けたメカニズム解明
木原 工; XU XIAO; 池田 暁彦
日本学術振興会, 科学研究費助成事業, 岡山大学, 基盤研究(B), 23H01672
01 Apr. 2023 - 31 Mar. 2026

Microscopic investigation of crystal structures at 100 Tesla using novel quantum beams
池田 暁彦
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, The University of Electro-Communications, Grant-in-Aid for Scientific Research (B), 23H01121
01 Apr. 2023 - 31 Mar. 2026

先端量子ビームによる物質の極限環境量子状態の解明
池田暁彦
文科省卓越研究員
Nov. 2021 - Mar. 2025

ポータブルパルス超強磁場発生装置 PINK による XFEL-100 テスラ共用実験
池田暁彦
SACLA/SPring-8基盤開発プログラム
Apr. 2021 - Mar. 2024

Study of the spin-lattice coupling using a single-shot x-ray measurement in ultrahigh magnetic fields
松田 康弘; 池田 暁彦; 久保田 雄也
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, The University of Tokyo, Grant-in-Aid for Challenging Research (Pioneering), X線は物質の構造や電子状態を微視的に明らかにする優れたプローブであり、磁場中で起こる様々な量子現象を理解するために、強磁場環境下でのX線実験技術 の開発は興味深く重要である。世界的に放射光X線とパルス強磁場を組み合わせて40テスラの実験が可能となっているが、現状の技術の延長では磁場の上限は50 テスラ程度にとどまる。マイクロ秒の超高速磁場を用いれば100テスラ以上の超強磁場X線実験が可能となるが、X線の光源もシングルショットで十分な強度を有する自由電子レーザー(XFEL)を用いることが必須となる。本年度、パルス超強磁場発生可能となるシステムを構築し、実際にその装置を用いたXFEL実験を兵庫県の自由電子レーザー施設SACLAにて2021年5月25~28日(課題番号2021A8063)および、2022年2月22~25日(課題番号2021B8064)で行った。最大77テスラの磁場を安全に発生し、実際にその下でX線回折計測に成功したことで、X線回折実験の世界記録を大きく上回ることができた。2021年5月の実験では、Mn酸化物BiCa0.5Mn0.5O3における磁場誘起電荷秩序融解に伴う構造相転移をX線回折でとらえ、結果はApplied Physics Letter誌に論文掲載された。BiCa0.5Mn0.5O3は、これまでに50テスラ付近で相転移が起こることが予想されていたが、実際に結晶構造の変化を確かめることはできていなかった。さらに、この物質は低温では相転移の動的挙動が緩慢になる傾向が磁化測定からわかっており、結晶格子変形との関連は今後興味深い研究テーマである。また、2022年2月には(Pr,Y)CaCoO3における磁場中X線回折実験を低温で行い、Prの価数転移とCoのスピン転移による構造相転移の観点から現在結果を解析・考察中である。, 20K20521
30 Jul. 2020 - 31 Mar. 2023

プラセオジウム系コバルト酸化物における磁気超流動性の検証
加藤科学振興会, Principal investigator
Apr. 2022 - Mar. 2023

磁気ひずみの精密計測による磁気の超流動・常流動転移の探索
池谷科学技術振興財団, Principal investigator
Apr. 2022 - Mar. 2023

超高精度2軸回転磁歪計測システムによる回転対称性の破れた磁気状態の探索
精密測定技術振興財団, 研究助成, 電気通信大学, Principal investigator
Apr. 2022 - Mar. 2023

Superfluidity at room temperature realized by magnetic field
Akihiko Ikeda
TEPCO Memorial Foundation, Research Grant (Basic Research), University of Tokyo, Principal investigator
Apr. 2019 - Mar. 2022

Investigation of Bose-Einstein condensation of triplet exciton in cobaltites
Ikeda Akihiko
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, The University of Tokyo, Grant-in-Aid for Early-Career Scientists, We have carried out a study to clarify the origin of the high-magnetic field induced phases of LaCoO3. It has been found that there are two novel phases up above 100 T region. The candidate for the novel phases are the crystallizations of spin-state degree of freedom (SSC: Spin-state crystal) and the Bose-Einstein condensation of spin-state degree of freedom (EC: Excitonic condensation). We have developed a magnetostriction measurement system for up above 100 T region utilizing the fiber Bragg grating strain gauge and implementing a very high-speed 100 Mhz detection system. We carried out a series of magnetostriction measurement of LaCoO3. We observed magnetostriction plateaux for both of the two novel phases. We concluded that the two novel phases are both originating in SSCs rather than EC., 18K13493
01 Apr. 2018 - 31 Mar. 2020

Investigation of spin state crystallization in a cobaltite
Ikeda Akihiko; Matsuda Yasuhiro H.; Sato Keisuke
Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, The University of Tokyo, Grant-in-Aid for Young Scientists (B), Principal investigator, In this research project, we have investigated a long standing problem of the spin-crossover of a cobaltite. Previous studies have focused on its temperature evolution, whereas we have applied a new axis of ultrahigh-magnetic fields along with the temperature evolution. We have explored in a wide range of temperature and magnetic field, resulting in a discovery of anomalous spin-state ordered phases above 100 T. The study opens a new area of multi-orbital Mott physics., 16K17738
01 Apr. 2016 - 31 Mar. 2019