Strongly Correlated Electron Physics Group consists of three guest professors belonging to national and independent research institutes. Research topics of each group are as follows.
Akihiko Fujiwara (Japan Synchrotron Radiation Research Institute)
The world's largest third-generation synchrotron
radiation facility SPring-8.
Our interest is unveiling the relation between structural characteristics and novel physical properties of matters via precise charge density and electrostatic potential distribution analyses. Our major technique is synchrotron radiation x-ray diffraction at SPring-8, and objectives are widely distributed from novel materials, such as superconducting materials, thermoelectric materials and organic semiconductors, to electronic devices.
Recently, we have succeeded in visualizing the subtle structural change which is a key role for the novel properties but has been invisible by the conventional methods. We are now conducting the design/development of novel materials and devices, based on the sophisticated analysis method utilizing the sophisticated synchrotron light source form SPring-8.
20-Tesla superconducting magnet with dilution refrigerator.
Taichi Terashima (National Institute of Materials Science)
Our main research areas are electronic structures, superconductivity, and magnetism of highly-correlated materials including iron-pnicitde superconductors, and Ce and U-based heavy fermions. We use high-field magnets installed at the Tsukuba Magnet Laboratory of the National Institute for Materials Science in Tsukuba. We especially focus on performing quantum oscillation measurements. The motion of electrons in magnetic fields is quantized, which results in quantum oscillation of physical properties of metals such as magnetization or resistivity as a function of magnetic field at very low temperatures. From quantum oscillation measurements we can determine the Fermi surface and effective masses of electrons, which are vital information to understand electronic structures of metals. Our main apparatus consists of a 20-Tesla superconducting magnet and dilution refrigerator, in which samples can be cooled down to 0.03 K. We can also apply high pressure of 3 GPa to samples to tune their electronic states.
Combination of sophisticated oxide growth techniques and
advanced analysis techniques using synchrotron radiation.
Hiroshi Kumigashira (KEK-Photon Factory)
The goal of our group is to control the novel physical properties appearing at the heterointerface of strongly correlated oxide. For this purpose, we utilize the synchrotron radiation spectroscopic techniques having the elemental selectivity, which enable us to determine the electronic, magnetic, and orbital structures in the nm-scale region at oxide interfaces. For example, the electronic structure at the interface is determined by photoemission spectroscopy (PES) and x-ray absorption spectroscopy (XAS), the magnetic structure by magnetic circular dichroism of XAS, and the orbital structure by linear dicroism of XAS. We aim to design the novel quantum phenomena by the best possible combination of sophisticated oxide growth techniques using laser molecular beam epitaxy and advanced analysis techniques using synchrotron radiation.