Combined study of microwave-power/linear-polarization dependence of the microwave-radiation-induced magnetoresistance oscillations in GaAs/AlGaAs devices

TL;DR

This study investigates how microwave power and polarization angle influence magnetoresistance oscillations in high mobility GaAs/AlGaAs devices at low temperatures, revealing nonlinear power effects and polarization dependence.

Contribution

It provides the first combined analysis of microwave power and polarization dependence on magnetoresistance oscillations in GaAs/AlGaAs heterostructures.

Findings

Magnetoresistance shows nonlinear dependence on microwave power.

Oscillatory resistance varies with cosine square of polarization angle.

Results partially align with existing theoretical models.

Abstract

We report the results of a combined microwave polarization-dependence and power-dependence study of the microwave-radiation-induced magnetoresistance oscillations in high mobility GaAs/AlGaAs heterostructure devices at liquid helium temperatures. The diagonal resistance was measured with the magnetic field fixed at the extrema of the radiation-induced magnetoresistance oscillations, as the microwave power was varied at a number of microwave polarization angles. The results indicate a nonlinear relation between the oscillatory peak or valley magnetoresistance and the microwave power, as well as a cosine square relation between the oscillatory peak or valley magnetoresistance and the microwave polarization angle. The main features are briefly compared with the predictions of existing models.