Evolution of the linear-polarization-angle-dependence of the radiation-induced magnetoresistance-oscillations with microwave power

TL;DR

This study investigates how microwave power influences the polarization angle dependence of radiation-induced magnetoresistance oscillations in high mobility GaAs/AlGaAs 2D electron systems, revealing non-linear effects at high power levels.

Contribution

It demonstrates the evolution of the polarization dependence with microwave power and identifies non-linear distortions in the oscillation amplitude at high power levels.

Findings

Non-linear power dependence distorts the cosine-square relation.

Evolution of Rxx versus θ with increasing microwave power.

High power causes non-linear effects in magnetoresistance oscillations.

Abstract

We examine the role of the microwave power in the linear polarization angle dependence of the microwave radiation induced magnetoresistance oscillations observed in the high mobility GaAs/AlGaAs two dimensional electron system. Diagonal resistance $R_{xx}$ was measured at fixed magnetic fields corresponding to the photo-excited oscillatory extrema of $R_{xx}$ as a function of both the microwave power, $P$, and the linear polarization angle, $\theta$. Color contour plots of such measurements demonstrate the evolution of the $R_{xx}$ versus $\theta$ line shape with increasing microwave power. We report that the non-linear power dependence of the amplitude of the radiation-induced magnetoresistance oscillations distorts the cosine-square relation between $R_{xx}$ and $\theta$ at high power.