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Kato Group

Associate Professor KATO, Takeo
Research Associate FUJII, Tatsuya

Research Subjects

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

Our laboratory is engaged in extensive theoretical research on transport properties in the fields of mesoscopic and spintronics. Research on mesoscopic systems has long focused on the quantum mechanical properties of electrons. We are still pursuing new phenomena such as non-equilibrium multi-embodiment phenomena, non-equilibrium noise, and strong external field-driven phenomena. In the field of spintronics, various spin transport phenomena are being studied, mainly in current and heat/spin conversion phenomena. 

In order to respond to these developments, our laboratory utilizes a wide range of theoretical approaches, including non-equilibrium statistical mechanics, quantum field theory, and many-body quantum theory. Specific research examples include spin transport at magnetic-metal interfaces, heat transport phenomena considering many-body effects in superconducting circuits, the nonequilibrium transport properties of Kondo quantum dots, and the generation of spin current in solids by light. We are also working closely with experimental groups in ISSP.

A two-level system coupled to two heat baths and an apparatus for continuous quantum measurement. The quantum measurement of the two-level system affects the heat current from the left to the right lead, which is called backaction.
Illustration of spin Hall magnetoresistance. Spin absorption at the interface changes according to the orientation of the Néel vector of the antiferromagnetic insulator, and the magnitude of the magnetoresistance changes.

Publications and Research Highlights