Cyclotron resonance harmonics in the ac response of a 2D electron gas with smooth disorder

TL;DR

This paper investigates the frequency-dependent conductivity of 2D electrons in a magnetic field with smooth disorder, revealing oscillatory behavior linked to Landau quantization that persists at high temperatures.

Contribution

It provides a theoretical analysis of cyclotron resonance harmonics in the ac response of 2D electron gases with smooth disorder, connecting to recent experimental findings.

Findings

Oscillatory structure in conductivity persists at high temperatures.

Landau quantization significantly influences ac response.

Theoretical results relate to recent photoconductivity experiments.

Abstract

The frequency-dependent conductivity $\sigma_{xx}(\omega)$ of 2D electrons subjected to a transverse magnetic field and smooth disorder is calculated. The interplay of Landau quantization and disorder scattering gives rise to an oscillatory structure that survives in the high-temperature limit. The relation to recent experiments on photoconductivity by Zudov {\it et al.} and Mani {\it et al.} is discussed.