Two dimensional electron gas driven by strong alternating electric field

TL;DR

This paper investigates the behavior of a two-dimensional electron gas under strong, slow alternating electric fields, revealing non-equilibrium quantum states, Landau level broadening, and a kinetic transition influenced by electron-phonon interactions.

Contribution

It develops a quasistatic approximation for driven disordered 2D electron gases and analyzes the effects of strong ac-fields on Landau level broadening and electron transport.

Findings

Landau level broadening is Lorentzian and inversely proportional to ac-field amplitude.

In the absence of electron-phonon interaction, the electron distribution is constant in the last Landau level with zero dc-conductivity.

A kinetic transition from phonon cooling to phonon heating is predicted.

Abstract

2D Fermi liquid driven by uniform alternating electric field at zero temperature may remain in quantum coherent non-equilibrium state. We develop a quasistatic approximation for strong and slow ac-fields and solve the problem of driven disordered 2D electron gas in high non-overlapping Landau levels. The broadening of Landau level has the Lorentz form and is inversely proportional to the amplitude of the ac-field. In the absence of electron-phonon interaction the electron distribution function is constant within the last Landau level and the diagonal dc-conductivity is zero. For weak electron-phonon interaction the dc-conductivity is anisotropic. A kinetic transition from the phonon cooling to the phonon heating is predicted.