In this work, we investigate the spin and valley transport properties of a $\mathrm{W}{\mathrm{Se}}_2$ monolayer placed on top of a ferromagnetic insulator. We are interested in controlling the transport properties by applying external potentials to the system. To obtain spin and valley polarizations, we consider a single- and a double-barrier structure with gate potentials. We analyze how the efficiency of these polarized transport properties depends on the gate-potential intensities and geometrical configurations. Additionally, we investigate how the spin and valley transport properties are modified when an ac potential is applied to the system. We obtain a controllable modulation of the spin and valley polarizations as a function of the intensity and frequency of the ac potential, mainly in the terahertz range. These results validate the proposal of double quantum well structures of $\mathrm{W}{\mathrm{Se}}_2$ as candidates to provide spin- and valley-dependent transport within an optimal geometrical parameter regime.

• Received 5 January 2021
• Revised 25 February 2021
• Accepted 9 March 2021

DOI:https://doi.org/10.1103/PhysRevApplied.15.034069