Spin and Valley Filter Based on Two-Dimensional <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"><mml:mi mathvariant="normal">W</mml:mi><mml:msub><mml:mi>Se</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:math> Heterostructures

In this work, we investigate the spin and valley transport properties of a $\mathrm{W}{\mathrm{Se}}_{2}$ monolayer placed on top ferromagnetic insulator. We are interested in controlling by applying external potentials to system. To obtain polarizations, consider single- double-barrier structure with gate potentials. analyze how efficiency these polarized depends gate-potential intensities geometrical configurations. Additionally, modified when an ac potential is applied controllable modulation polarizations as function intensity frequency potential, mainly terahertz range. These results validate proposal double quantum well structures candidates provide spin- valley-dependent within optimal parameter regime.