Comparative study of microwave radiation-induced magnetoresistive oscillations induced by circularly- and linearly- polarized photo-excitation

TL;DR

This study compares how linearly- and circularly-polarized microwave radiation differently induce magnetoresistance oscillations in high mobility GaAs/AlGaAs 2DES, revealing distinct sensitivities to polarization orientation.

Contribution

It provides a direct comparison of magnetoresistance responses under different microwave polarizations, highlighting the profound difference in their angular dependence.

Findings

Linearly polarized radiation causes a sinusoidal magnetoresistance response with angle.

Circularly polarized radiation induces oscillations that are insensitive to polarization angle.

Both polarizations produce similar oscillations at low magnetic fields.

Abstract

A comparative study of the radiation-induced magnetoresistance oscillations in the high mobility GaAs/AlGaAs heterostructure two dimensional electron system (2DES) under linearly- and circularlypolarized microwave excitation indicates a profound difference in the response observed upon rotating the microwave launcher for the two cases, although circularly polarized microwave radiation induced magnetoresistance oscillations observed at low magnetic fields are similar to the oscillations observed with linearly polarized radiation. For the linearly polarized radiation, the magnetoresistive response is a strong sinusoidal function of the launcher rotation (or linear polarization) angle, {\theta}. For circularly polarized radiation, the oscillatory magnetoresistive response is hardly sensitive to {\theta}.