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Kato Group

Research Associate SANO, Ryotaro

Research Subjects

  • Transport phenomena in mesoscopic systems
  • Fundamental theory of spintronic devices
  • Nonequilibrium and transport properties in solids

Our laboratory focuses on mesoscopic physics and spintronics, investigating the nonequilibrium properties of quantum transport phenomena. Combining nonequilibrium statistical mechanics, quantum field theory, and many-body electron theory, we aim to understand the novel phenomena arising from electron, spin, and heat currents at the nanoscale, and to establish new concepts in condensed matter physics.

In the mesoscopic field, we study nonequilibrium many-body effects and quantum noise in two-dimensional electron gas. In spintronics, we develop the theoretical foundations of spin transport phenomena, including the spin Hall effect and the spin Seebeck effect. Our research extends across a wide range of materials and degrees of freedom, encompassing topics such as spin and orbital current transport at magnetic/metal interfaces and quantum transport of anyons in fractional quantum Hall systems. We also actively pursue collaborative research with experimental groups both within and outside our institute.

Our goal is to pioneer next-generation quantum materials research, advancing both the fundamental physics of quantum transport and its applications in the control of spin and heat functionalities.

Frequency dependence of the microwave absorption rate in a fractional quantum Hall droplet. The plots and solid lines show the results of quantum Monte Carlo simulation and perturbation theory, respectively, for varying quasiparticle tunneling strengths at a quantum point contact (QPC).
Orbital accumulation induced by chiral phonons. The figure shows the magnitude of orbital accumulation when only the energy of a single electron orbital is varied. The inset displays the Fermi surface at each energy.

Publications and Research Highlights