Plasmon–Phonon Coupling in Radiation‐Induced Resistance Oscillations: Beating Pattern and Phase Reversal

Abstract

This article presents a theoretical study on the experimental observation of two different kinds of beating patterns in the microwave‐induced resistance oscillations at very low magnetic field in a high mobility two‐dimensional electron system. In the first pattern there was no phase reversal through the beat, however, the latter experiments present a clear phase reversal of π. Based on a model that considers that the beating pattern is produced as a result of the coupling between a system of electron Landau states harmonically driven by radiation and an acoustic phonon mode, the contradictory results are explained through a different intensity coupling in terms of amplitude. In the scenario of the non‐phase‐reversal case, the dependence on radiation frequency and temperature is studied as well as the possibility of observation of more than one beat by lowering temperature and microwave power. It is concluded that both results can be explained with the same theoretical model that in turn is based on the microwave‐driven electron orbit model that was previously developed to explain microwave‐induced resistance oscillations.