Electric fields induced spin and/or valley polarization in Weiss oscillations of monolayer 1{\it T}$^{\prime}$-$\mathrm{MoS}_{2}$

Abstract

Monolayer 1{\it T}$^{\prime}$-$\mathrm{MoS}_{2}$ exhibits spin- and valley-dependent massive tilted Dirac cones with two velocity correction terms in low-energy effective Hamiltonian. We theoretically investigate the longitudinal diffusive magneto-conductivity of monolayer 1{\it T}$^{\prime}$-$\mathrm{MoS}_{2}$ by using the linear response theory. It is shown that the Weiss oscillations are polarized in spin and valley degrees of freedom, under uniform electric fields and a weak one-dimensional spatially-periodic electrostatic potential modulation. The spin polarization, the valley polarization and the spin-valley polarization can be switched by flipping the external electric fields. The polarization is found not only in the amplitudes but also in the periods of the Weiss oscillations. It is found that the period polarization in Weiss oscillations originates from the polarized effective Fermi energies or the polarized Landau level spacing scales. In Weiss oscillations, polarization in amplitude does not imply the presence of polarization in period, whereas polarization in period is accompanied by polarization in amplitude. The superposition of polarization in amplitude and polarization in period enables the appearance of considerable polarization in Weiss oscillations under relatively weak external electric fields.