Sub-linear radiation power dependence of photo-excited resistance oscillations in two-dimensional electron systems

TL;DR

This study reveals that the amplitude of radiation-induced resistance oscillations in a 2D electron system increases sub-linearly with radiation power, following a power law with an exponent less than one, explained by a radiation-driven electron orbits model.

Contribution

It demonstrates a sub-linear power dependence of resistance oscillation amplitude and explains this behavior using a radiation-driven electron orbits model.

Findings

Amplitude scales as P^α with α<1

The sub-linear dependence varies with temperature and frequency

The model explains the linear dependence on electric field

Abstract

We find that the amplitude of the $R_{xx}$ radiation-induced magnetoresistance oscillations in GaAs/AlGaAs system grows nonlinearly as $A \propto P^{\alpha}$ where $A$ is the amplitude and the exponent $\alpha < 1$. %, with $\alpha \rightarrow 1/2$ in %the low temperature limit. This striking result can be explained with the radiation-driven electron orbits model, which suggests that the amplitude of resistance oscillations depends linearly on the radiation electric field, and therefore on the square root of the power, $P$. We also study how this sub-linear power law varies with lattice temperature and radiation frequency.