Photovoltaic Hall effect in two-dimensional electron gas: Kinetic theory

TL;DR

This paper develops a microscopic kinetic theory to analyze the photovoltaic Hall effect and intraband optical transitions in two-dimensional electron gases, revealing how scattering mechanisms and temperature influence transverse photoconductivity.

Contribution

It provides a comprehensive analytical framework for understanding photoconductivity in 2DEG with various dispersions and scattering mechanisms, including effects of electron-electron collisions.

Findings

Transverse photoconductivity peaks at frequencies near inverse energy relaxation time.

Current direction depends on scattering mechanism at higher frequencies.

Electron-electron collisions influence thermalization and photoconductivity behavior.

Abstract

We study theoretically transverse photoconductivity induced by circularly polarized radiation, i.e. the photovoltaic Hall effect, and linearly polarized radiation causing intraband optical transitions in two-dimensional electron gas (2DEG). We develop a microscopic theory of these effects based on analytical solution of the Boltzmann equation for arbitrary electron spectrum and scattering mechanism. We calculate the transverse photoconductivity of 2DEG with parabolic and linear dispersion for short-range and Coulomb scatterers at different temperatures. We show that the transverse electric current is significantly enhanced at frequencies comparable to the inverse energy relaxation time, whereas at higher frequencies the excitation spectrum and the direction of current depend on the scattering mechanism. We also analyse the effect of thermalization processes caused by electron-electron collisions on the photoconductivity.