Research fields
１Strongly
correlated electron systems
１-１ Mott transition in the 2D Hubbard model
１-２ Universality of Mott transition
１-３ 1D orbital excitation in perovskite vanadium
oxides
１-４ Quantum
melting of spin ice
２General
theory of nonequilibrium-nonlinear phenomena by electromagnetic field
２-１ Gauge-covariant Wigner representation of the
Keldysh formalism
２-２ Hall effect
２-３ Zener tunneling and breakdown
３Anomalous
Hall transport phenomena
３-１ Intrinsic Berry-phase
mechanism and extrinsic mechanisms
３-２ Universal scaling relation in dirty ferromagnetic metals
３-３ Anomalous Nernst-Ettingshausen and Leduc-Righi effects
４Spin
Hall effect
５Topological
nature of ferroelectric polarization
５-１ Quantum charge pumping
５-２ Quantum theory of capacitance
６Multiferroics
６-１ Cluster analysis of electric polarization of
magnetic origin
６-２ 1D spin-1/2 multiferroics: chiral soliton
６-３ Spin cholesteric (chiral nematic) phase in
frustrated classical spin systems
６-４ Schwinger-boson mean-field theory of
low-dimensional frustrated quantum spin systems
６-５ Toroidal moment
and
many others.