Condensed matter system with strong electron correlation host numerous intriguing phenomena, such as the superconductor-metal-insulator transition, (anti-)ferromagnetism, ferroelectricity, multiferroelectricity, and so on, and such are arising from strong interaction among fundamental degrees of freedom in the solid, i.e., charge, spin, orbital, and lattice. Their proper understanding is therefore crucial to deepen our knowledge of the nature and also for the technical usage of novel functionality.

We investigate novel electric and magnetic phenomena emerging mainly in transition metal oxides and van der Waals materials by using state-of-the-art spatio-temporal optical spectroscopy techniques, and aim at revealing working principles and designing new functional devices by elucidating underlying couplings among charge, spin, and lattice (phonon). Following topics are being investigated.

(i) We investigate Mott metal-insulator transition, reveal novel metallic states near the phase transition, and hence contribute to develop ultrafast and highly efficient functional devices based on them.

(ii) We investigate ultrafast (~ps) and local (~nm) transports of charge, spin, and phonon, and establish understanding schemes beyond Ohm's law or Fourier's law.

(iii) We investigate non-equilibrium states of lattice, charge, and/or magnetic sub-systems, and elucidate strong coupling effects in the course of the relaxation to the equilibrium states.