Takeyama, Shojiro
Professor
International MegaGauss Science Laboratory
University of Tokyo
Japan
Biography
We are engaged in development for generating ultra-high magnetic fields above 100 T, and pursue the solid-state science realized under such an extreme condition. We employ two methods for the ultra-high magnetic field generation, one is the electro-magnetic flux compression (EMFC) and the other is the single-turn coil (STC) method. We have established a new type of coil for the EMFC, and currently the maximum magnetic field is 730 T. This value is the highest achieved thus far in an indoor setting in the world. Further development is underway for achieving much higher fields, more precise and reliable measurements for the solid-state physics. We are now involved in construction of ultra-high magnetic field generator system under the 1000 T project. The horizontal and vertical (H- and V-) STCs are used for more precise measurements up to 300 T, respectively, in accordance with their magnetic field axes. The H-STC is mainly used for magneto-optical measurements by use of laser optics, whilst the V-STC is more suitable for the study of low-temperature magnetization in a cryogenic bath. We are conducting the studies on magneto-optics of carbon nano-materials or of semiconductor nano-structures as well as on the critical magnetic fields in superconducting materials and on the high-field magnetization processes of the magnetic materials with highly frustrated quantum spin systems.
Research Interest
Technical developments for ultra-high magnetic field magnets above 100 T and for solid-state physics measurements Magneto-optics in ultra-high magnetic fields Magnetization processes of magnetic materials and the critical magnetic field in superconducting materials in ultra-high magnetic fields
Publications
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Magnetic transitions under ultrahigh magnetic fields of up to 130 T in the breathing pyrochlore antiferromagnet LiInCr4O8: Y. Okamoto, D. Nakamura, A. Miyake, S. Takeyama, M. Tokunaga, A. Matsuo, K. Kindo and Z. Hiroi, Phys. Rev. B 95 (2017) 134438(1-5).
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Magnetization Process of the S = 1/2 Two-Leg Organic Spin-Ladder Compound BIP-BNO: K. Nomura, Y. H. Matsuda, Y. Narumi, K. Kindo, S. Takeyama, Y. Hosokoshi, T. Ono, N. Hasegawa, H. Suwa and S. Todo, J. Phys. Soc. Jpn. 86 (2017) 104713(1-3).
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Electric Polarization Induced by Spin Ordering under Magnetic Fields in Distorted Triangular Lattice Antiferromagnet RbCoBr3: Y. Nishiwaki, M. Tokunaga, R. Sakakura, S. Takeyama, T. Kato and K. Iio, J. Phys. Soc. Jpn. 86 (2017) 044701(1-7).
