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 electromagnetic 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 985 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 200 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.
Newly-developed ultra-high magnetic field generator of the electro-magnetic flux compression method. The 5 MJ and 2 MJ fast condenser bank are capable of supplying several mega-amperes, which are injected into a primary coil through the collector plate. By upgrading the performance such as the maximum charging voltage and energy transfer efficiency, ultra-high magnetic fields exceeding 1000 T are planned to generate.
The world record for the highest magnetic field generated in laboratories housed in a building has been broken, achieving 985 T and approaching 1000 T. This is applicable to the measurement of physical properties by the electromagnetic flux compression (EMFC) method. Faraday rotation of quartz was used to monitor the magnetic fields that were measured close to the highest value. Record magnetic fields, close to 1000 T, were detected showing that it is possible to generate such flux densities and indicating that it is also possible to measure physical properties in super-strong magnetic fields in the region of 1000 T.
†*Magnetoelastic couplings in the deformed kagome quantum spin lattice of volborthite: A. Ikeda, S. Furukawa, O. Janson, Y. H. Matsuda, S. Takeyama, T. Yajima, Z. Hiroi and H. Ishikawa, Phys. Rev. B99 (2019) 140412(R) 1-5.
†Ultra-high magnetic field magnetic phases up to 130 T in a breathing pyrochlore antiferromagnet LiInCr4O8: M. Gen, D. Nakamura, Y. Okamoto and S. Takeyama, Journal of Magnetism and Magnetic Materials473 (2019) 387-393.
†*Pauli-limit upper critical field of high-temperature superconductor La1.84Sr0.16CuO4: D. Nakamura, T. Adachi, K. Omori, Y. Koike and S. Takeyama, Sci Rep9 (2019) 16949 1-8.
*A series of magnon crystals appearing under ultrahigh magnetic fields in a kagomé antiferromagnet: R. Okuma, D. Nakamura, T. Okubo, A. Miyake, A. Matsuo, K. Kindo, M. Tokunaga, N. Kawashima, S. Takeyama and Z. Hiroi, Nature Communications10 (2019) 1229(7).
†*Ultrahigh-Magnetic-Field Magnetization of Multi-Kagome-Strip (MKS) Lattice Spin-Frustrated Magnet K2Mn3(OH)2(VO4)2: D. Otsuka, H. Sato, A. Matsuo, K. Kindo, D. Nakamura and S. Takeyama, J. Phys. Soc. Jpn.87 (2018) 124701 1-7.
† Joint research with outside partners. * Joint research between groups within ISSP.