Low-energy effective theory and anomalous Hall effect in monolayer $\mathrm{WTe}_2$

TL;DR

This paper develops a symmetry-based low-energy theoretical model for monolayer WTe2, linking measurable spin and Hall effects to underlying spin-orbit interactions and Dirac band tilt.

Contribution

It introduces a comprehensive eight-band model that simplifies to a Dirac model near the Dirac points, enabling detailed analysis of spin-orbit effects in monolayer WTe2.

Findings

Model captures essential low-energy physics of monolayer WTe2.

Measurements of spin susceptibility and Hall conductivity reveal spin-orbit coupling parameters.

The model links experimental observables to fundamental electronic properties.

Abstract

We develop a symmetry-based low-energy theory for monolayer $\mathrm{WTe}_2$ in its 1T$^{\prime}$ phase, which includes eight bands (four orbitals, two spins). This model reduces to the conventional four-band spin-degenerate Dirac model near the Dirac points of the material. We show that measurements of the spin susceptibility, and of the magnitude and time dependence of the anomalous Hall conductivity induced by injected or equilibrium spin polarization can be used to determine the magnitude and form of the spin-orbit coupling Hamiltonian, as well as the dimensionless tilt of the Dirac bands.