Microwave strengths to induce magnetoresistance oscillations in high-mobility 2DES in a photon-assisted impurity scattering model

TL;DR

This paper investigates how microwave electric field strength influences magnetoresistance oscillations in high-mobility 2D electron systems, highlighting the dependence on impurity potential types within a photon-assisted impurity scattering model.

Contribution

It demonstrates the dependence of microwave intensity requirements on impurity potential form for inducing magnetoresistance oscillations in 2D electron systems.

Findings

Lower microwave fields induce oscillations with background impurity scattering.

Higher microwave fields are needed for remote impurity scattering.

Oscillation features are insensitive to elastic scattering behavior.

Abstract

It is shown that, although the major feature of the microwave-induced magnetoresistance oscillations in two-dimensional (2D) electron systems is insensitive to the behavior of the elastic scattering in the photon-assisted impurity scattering model [X.L. Lei and S.Y. Liu, Phys. Rev. Lett. 91, 226805 (2003)], the required microwave intensity to induce an effective oscillation depends strongly on the form of the impurity potential. A microwave electric field of a few Volts per cm in amplitude is sufficient to induce remarkable oscillations if the elastic scatterings are due to background charged impurities, which is an order of magnitude smaller than that needed if the scatterings are due to remote charged impurities located 60 nm away from 2D electron gas.