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Otani Group

Professor OTANI, Yoshichika
Research Associate ISSHIKI, Hironari

Research Subjects

  • Topological spintronics
  • Molecular spintronics
  • Elucidation of the mechanism of the magnetic spin Hall effect and development of functionality
  • Efficient pure spin current generation by magnon-phonon coupling

The concept of “spin current”, which appeared at the end of the 20th century, established the principle of effectively using electric and spin currents. Thereby, spintronics research has evolved as a “spin conversion science” in which quasiparticles such as electric charges, spins, phonons, photons, and magnons are converted to each other through spins in solids. More recently, this spin conversion science has evolved into strong coupling spintronics, producing novel coupled quasiparticles, such as magnetic polarons. Since these spin-mediated conversion/coupling phenomena often occur in the nanoscale region near the relatively simple junction interface, they have excellent versatility and applicability. From the viewpoint of fundamental solid-state physics, our laboratory is developing novel quasiparticle conversions and coupling mediated by spins and elucidating their mechanisms. We also research and develop nanoscale spin conversion/coupling devices based on the quasiparticle conversion and coupling that we have elucidated using microfabrication technology.

Nonreciprocal propagation of magnetoacoustic waves in Ta/CoFeB/MgO. (A) Device schematics of SAWs coupling to an FM layer at gigahertz frequencies. (B) Attenuation of acoustic waves, P±k, near a spin-wave resonance condition for SAW numbers +k and −k.
Giant spin Hall effect of a Weyl ferromagnet Co2MnGa. (a) SEM image of a non-local spin valve structure. (b) The non-local spin valve signals with and w/o Co2MnGa wire. (c) The signals of spin Hall effect and it’s inverse of Co2MnGa.

Publications and Research Highlights