Gate controllable spin filteration and spin separation in transition-metal-dichalcogenide monolayers for room temperature applications

Monolayer transition-metal dichalcogenides (TMDs) are semiconductors with direct gaps at the corners of the hexagonal Brillouin zone. Strong spin-orbit coupling in the absence of inversion symmetry yields spin-split valence bands in the TMDs around the two inequivalent valleys, which are almost fully spin-polarized without requiring magnetic fields. By exploiting these salient features of the electronic states, we propose two spintronics applications based on TMD monolayers, a spin-filter and a spin-separator. We demonstrate the high efficiency (output current with nearly 100% spin-polarization) of our proposed spin-filter/separator through quantum transport computations. Since spin-splitting energies range from 100-500 meV in the TMDs, our spin filter/separator is suitable for room temperature applications.