Experimental observation of coupled valley and spin Hall effect in p‐doped WSe₂ devices

Abstract

Abstract It is generally accepted that perpendicular magnetic anisotropy (PMA) magnets are preferred over in‐plane magnetic anisotropy (IMA) magnets in data storage applications owing to their large thermal stability even at ultra‐scaled dimensions. To efficiently and deterministically switch a PMA, out‐of‐plan spin current is required. However, conventional giant spin Hall effect (GSHE) materials only produce spin currents with in‐plane polarization. Our work, on the other hand, demonstrated for the first time that out‐of‐plane spin currents can indeed be generated by applying electric filed to monolayer WSe 2 at room temperature and the spin information was detected by a graphene channel. Supported by theoretical calculations, we found that the interfacial polarization between graphene and WSe 2 to be ~38% assuming the ferromagnetic detector's polarization efficiency to be ~4%. Moreover, the spin polarization is determined by the polarity of the applied electric field. image