Microwave-induced suppression of dissipative conductivity and its Shubnikov -- de Haas oscillations in two-dimensional electron systems: Effect of dynamic electron localization

TL;DR

This paper develops a model explaining how microwave radiation suppresses dissipative conductivity and smears Shubnikov–de Haas oscillations in 2D electron systems by reducing impurity scattering, aligning with recent experimental results.

Contribution

The paper introduces a theoretical model for microwave photoconductivity in 2DESs that accounts for intra-Landau level transitions and impurity scattering suppression, providing insights into experimental phenomena.

Findings

Microwave radiation decreases dissipative conductivity in 2DES.

The model predicts conductivity dependence on microwave and cyclotron frequencies.

Results align with recent experimental observations of conductivity suppression.

Abstract

We present a model for microwave photoconductivity in two-dimensional electron systems (2DESs) in a magnetic field at the microwave frequencies lower that the electron cyclotron frequency when the intra-Landau level (LL) transitions dominate. Using this model, we explain the effect of decrease in the 2DES dissipative conductivity (and resistivity) and smearing of its Shubnikov -- de Haas oscillations by microwave radiation observed recently \cite{1,2}. The model invokes the concept of suppression of elastic impurity scattering of electrons by the microwave electric field. We calculated the dependence of the 2DES conductivity associated with intra-LL transitions as a function of the radiation and cyclotron frequencies and microwave power. The obtained dependences are consistent with the results of recent experimental observations \cite{1,2}.