Spin-valley-polarized Weiss oscillations in monolayer 1{\it T}$^{\prime}$-\ce{MoS2}

TL;DR

This paper theoretically studies spin-valley-polarized Weiss oscillations in monolayer 1T'-MoS2, revealing how external electric and magnetic modulations induce polarization effects linked to the material's tilted Dirac cones and spin-orbit coupling.

Contribution

It introduces a theoretical analysis of how external modulations cause spin-valley polarization in Weiss oscillations in monolayer 1T'-MoS2, highlighting the role of tilted Dirac cones and spin-orbit coupling.

Findings

Weiss oscillation splits into two branches near the spin-orbit gap.

Spin-valley polarization occurs under electric potential modulation when near the gap.

Polarization can also arise from magnetic field modulation far from the gap.

Abstract

Monolayer 1{\it T}$^{\prime}$-\ce{MoS2} 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 magnetoconductivity of monolayer 1{\it T}$^{\prime}$-\ce{MoS2} by using the linear response theory. It is shown that, when the Fermi level is close to the spin-orbit coupling gap, the Weiss oscillation splits into two branches and exhibits spin-valley polarization in the presence of both a spatial periodic electric potential modulation in the lateral direction and a nonzero perpendicular electric field. The spin-valley polarization stems from the interplay between the tilted Dirac cones, the spin-orbit coupling gap, and the external electric potential modulation, and can be treated as a signature of monolayer 1{\it T}$^{\prime}$-\ce{MoS2}. When the Fermi level is far from the spin-orbit coupling gap, the spin-polarization appears in the Weiss oscillation under a magnetic field modulation in the lateral direction. This polarization behavior arises from the interplay between the tilted Dirac cones, the spin-orbit coupling, and the external magnetic field modulation, indicating that a finite spin-orbit coupling gap is not indispensable for polarization in the Weiss oscillation.