Circular polarization dependent study of the microwave photoconductivity in a two-dimensional electron system

TL;DR

This study investigates how circular polarization affects microwave photoconductivity in a 2D electron system, revealing resistance oscillations are unaffected by polarization sense except near cyclotron resonance, challenging existing theories.

Contribution

It provides the first detailed analysis of circular polarization effects on microwave photoconductivity in 2D electron systems, highlighting discrepancies with current theoretical models.

Findings

Resistance oscillations are immune to circular polarization sense.

Large resistance response occurs only near cyclotron resonance.

Photoconductivity behavior challenges existing theories.

Abstract

The polarization dependence of the low field microwave photoconductivity and absorption of a two-dimensional electron system has been investigated in a quasi-optical setup in which linear and any circular polarization can be produced in-situ. The microwave induced resistance oscillations and the zero resistance regions are notedly immune to the sense of circular polarization. This observation is discrepant with a number of proposed theories. Deviations only occur near the cyclotron resonance absorption where an unprecedented large resistance response is observed.