Renormalization of the valley Hall conductivity due to interparticle interaction

TL;DR

This paper develops a theoretical framework to understand how Coulomb interactions influence the valley Hall effect in two-dimensional gapped Dirac materials, considering different doping regimes and temperature effects.

Contribution

It introduces a model for Coulomb interaction-mediated contributions to the valley Hall effect, including electron-electron and electron-hole scattering in various doping regimes.

Findings

Renormalized valley Hall conductivity calculated for different regimes.

Electron-hole annihilation impacts VHE at higher temperatures.

Interparticle scattering predominantly occurs between particles in different valleys.

Abstract

We develop a theory of Coulomb interaction-mediated contribution to valley Hall effect (VHE) in two-dimensional non-centrosymmetric gapped Dirac materials. We assume that the bare valley Hall current occurs in the system due to the presence of disorder caused by impurities and is determined by the valley-selective anisotropic skew scattering. Applying the Boltzmann transport equation to describe the electron and hole transport in the material, we calculate the renormalized VHE conductivity due to electron-electron and electron-hole scattering processes, considering two regimes: (i) an $n$-doped monolayer hosting a degenerate electron gas, and (ii) an intrinsic semiconductor with the Boltzmann statistics of electron and hole gases. In both regimes, the dominant mechanism of interparticle scattering is due to particles residing in different valleys. Moreover, in case (ii), in addition to direct scattering, electron-hole annihilation starts to play a role with the increase in temperature. It might even become the dominant mechanism of the Coulomb interaction-mediated VHE.