High-efficiency spin and valley filter in a monolayer WSe2 superlattice modulated by an anti-handed off-resonance circularly polarized light

Abstract

Abstract We have theoretically studied spin and valley transport properties in an optically-controlled electromagnetic superlattice based on monolayer WSe2. Owing to the regulation of the anti-handed off-resonance circularly polarized light, we find that spin- and valley-dependent line-type resonant peaks appear in the transport forbidden region for small incident angles, so that 100 % high-efficiency spin-valley polarization can be obtained. The result indicates that the high-efficiency spin and valley filter can be more conveniently implemented based on the 2D transition metal dichalcogenides superlattice. In addition, the number of spin- and valley-dependent line-type resonant peaks is tunable using an incident angle, gate voltage and the width of the modulated regions.