Tsunetsugu, Hirokazu

Biography

Strongly correlated electron systems, particularly compounds including d- or f-orbital electrons, are the main subjects of our research. In these systems where electron-electron interactions are very strong, a variety of interesting phenomena emerge at low temperatures, and various magnetic orders, unconventional superconductivity and density waves are typical cases. Targets of our recent study include novel types of quantum order and quantum fluctuations in frustrated spin and strongly correlated electronic systems with multiple degrees of freedom. In these systems, many soft modes of fluctuations are coupled, and this affects the nature of quantum phase transitions, as well as electronic states and dynamical properties including transport phenomena. One of our recent achievements is about optical conductivity near an antiferromagnetic phase transition. We have shown that vertex corrections due to magnetic order and fluctuations provide a substantial contribution to optical conductivity, which is in sharp contrast to the behavior near the Mott transition in frustrated electron systems.

Research Interest

Electronic states of strongly correlated systems with d- or f-electrons Statistical physics of frustrated systems Theory of novel phases in quantum magnets Unconventional superconductivity in strongly correlated electron systems