Enhanced spin polarization and valley polarization in monolayer MoS₂ junctions

Special resonant modes in unique quantum structure can enhance spin and valley filtering effect. Hence we investigated resonant tunneling effect with large incident angles through single electric barrier in monolayer MoS₂ junctions consisting of normal/ferromagnetic/normal parts. We found that for large incident angles the spin- and valley-dependent line-type resonances appear in the transmission and conductance spectra, which results in the transmission probabilities of spin-up and spin-down electrons at K and [Formula: see text] valleys being all improved to 100[Formula: see text] but for different special gate voltage. Therefore, both the spin and valley polarizations are increased, the perfect 100[Formula: see text] spin and valley polarizations are observed. Furthermore, the numbers of the line-type resonant peaks are multiplied with the increasing of the barrier's width. And the spin- and valley-polarized direction can be switched by changing the gate voltage. These intriguing features indicate that a valley or spin filter with high accuracy and efficiency can be designed, which is controllable by the electric field.