Research Subjects
1: Study on magnetism of quantum spin systems
2: Study on magnetism and conductivity of strongly correlated electron systems
3: Development of non-destructive 100 T-magnet
4: Development of ultra-long pulse magnet
We carry out precise measurements under non-destructive
pulsed high magnetic fields that are generated by capacitor
banks and flywheel DC generator installed at the facility. Various
magnets have been developed at user’s requests. Up to now,
available field conditions for users are as follows.
1. Short pulse magnet: Pulse duration 5 ms, maximum field 75 T
2. Mid pulse magnet: Pulse duration 30 ms, maximum field 65 T
Short pulse magnet is used mainly for magnetization measurements
on insulating materials and Mid pulse magnet is used for
various measurements on metallic materials. Our magnet has
been breaking the world record of non-destructive mono-coil
field and we continue to develop a new magnet aiming at the
new world record of 100 T. We have installed the flywheel DC
generator on May 2008. The generator enables us to generate
longer pulsed field with the duration of 1-10 seconds. The Long
pulsed fields can provide much better conditions for precise
measurements that had been thought to be difficult before.
Tokunaga Laboratory
Research Subjects
1: Field-induced transitions in multiferroic materials
2: High-field studies on high temperature superconductors
3: High-speed polarizing microscope imaging in pulsed-high magnetic fields
4: Field-induced transitions in magnetic shape-memory alloys
The crossed-coupling among spin, charge, orbital, and lattice degrees of freedom causes changes in various physical properties in magnetic fields. We study novel physical phenomena in these cross-correlated materials with utilizing the world highest class of pulsed magnetic fields. To capture the essential aspects of the composite phase transitions, we have been developed many experimental probes that can detect the instantaneous changes of various physical properties. In particular, our high-speed polarizing microscope system provides us with unique opportunity to visualize the changes in crystallographic symmetry in pulsed high magnetic fields. With utilizing these special instruments, we are studying on magnetoelectric effects in ferroelectric magnets, field-induced melting of spin/orbital order in a parent compound of the iron-based superconductors, and martensitic transformation in magnetic shape-recovery alloys.
Matsuda Laboratory
Research Subjects
1: Quest of magnetic field-induced phase transitions of solid oxygen
2: Magnetic field-induced insulator.metal transition
3: Magnetization process of quantum spin systems
4: Electronic states of heavy fermions in high magnetic fields
We have been studying the electronic and magnetic properties of the matter in ultra-high magnetic fields exceeding 100 T in collaboration with Takeyama Group. Magnetic-field-induced phase transitions and cross over phenomena in strongly correlated systems are the main subjects.
Magnetic field can precisely control the electronic states through the Zeeman effect and Landau quantization. In ISSP, a 700-Tesla magnetic field is generated by the electro-magnetic flux compression method. Since the Zeeman energy in such a high field is larger than the energy corresponding to a room temperature, a significant field effect is expected. Specifically, the following subjects are studied: (1) Quest of magnetic fieldinduced phase transitions of solid oxygen, (2) Magnetic fieldinduced insulator.metal transition, (3) Magnetization process of quantum spin systems, and (4) Electronic states of heavy fermions in high magnetic fields. We also carry out the X-ray magneto-spectroscopy in pulsed high magnetic fields using synchrotron X-rays at the SPring-8 and KEK-PF. Elementand shell-selective X-ray magneto-spectroscopy is expected to uncover microscopic mechanisms of the magnetic-field-induced phenomena.
Kohama Laboratory
Under Construction
Osada Laboratory
Research Subjects
1: Quantum transport of Dirac electron system in graphene and zerogap organic conductors
2: Interlayer coherence and angle-dependent magnetotransport in layered conductors
3: Quantum transport of chiral surface state in multilayer quantum Hall systems
4: Charge and spin density waves under magnetic fields in low-dimensional organic conductors
5: Chaos and electron transport in Bloch electron systems under magnetic and electronic fields
Transport study of low-dimensional electron system and/or Dirac fermion systems in solids. To search for new phenomena in electron systems with small spatial structures or internal degrees of freedom, to clarify their mechanisms, and to control them for application. We have a great interest in quantum effects, topological effects, and many-body effects, which relate to singularity of band structure, pseudo-spin internal degrees of freedom, and commensurability among electron orbital motions, vortex (magnetic flux) configuration, and spatial structures (topology). Our targets are low-dimensional conducting crystals such as graphene (monolayer graphite) and organic conductors, and artificial semiconductor/superconductor micro-structures fabricated by advanced processing techniques like MBE or EB. We flexibly explore new transport phenomena and electronic states by electric, magnetic, and thermal measurements using precise field rotation, miniature pulse magnet, MEMS probes, etc. under magnetic fields and low temperatures. Recently, we have concentrated our studies on quantum transport of relativistic Dirac electrons in graphene and organic conductors.
