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Kato Group

member
Associate Professor KATO, Takeo
Research Associate FUJII, Tatsuya

Research Subjects

  • Transport phenomena in mesoscopic systems
  • Electronic properties of interacting electron systems
  • Fundamental theory of spintronics
  • Non-equilibrium statistical mechanics

We are conducting theoretical research on quantum transport properties of nanoscale devices using various methods. In the research field that is called mesoscopic systems for long time, there has been active research focusing on the quantum mechanical properties of electrons. In recent years, research has been advanced from new viewpoints such as non-equilibrium many-body effects, non-equilibrium noise, strong field driving phenomena, and spintronics. In response to these advances, our laboratory is conducting a wide range of theoretical research using non-equilibrium statistical mechanics, quantum field theory, and many-body theory. Recent examples include adiabatic pumping of nanoscale devices, spin transport at magnetic junctions, many-body effects in thermal transport phenomena in superconducting circuits, non-equilibrium transport properties of Kondo quantum dots, and high harmonic generation in solids. In addition, we are conducting various physical phenomena in condensed matter physics. The joint research with the experiment groups in Institute for Solid State Physics is also advanced.

Main panel: Temperature dependence of a spin current induced by spin pumping from a ferromagnetic insulator to a superconductor. Inset: A schematic of a ferromagnetic insulator/superconductor junction.
Upper panel: A superconducting circuit for realizing a superconducting qubit system coupled to the subohmic bath. Lower panel: A numerical result for the microwave reflection loss as a function of the frequency. α is the dimensionless qubit-reservoir coupling.

Publications and Research Highlights