Quantum and classical surface acoustic wave induced magnetoresistance oscillations in a 2D electron gas

TL;DR

This paper theoretically investigates how surface acoustic waves induce magnetoresistance oscillations in a 2D electron gas, revealing classical and quantum effects, and predicts zero-resistance states at high SAW amplitudes.

Contribution

It introduces a comprehensive theoretical model describing classical and quantum contributions to SAW-induced resistivity oscillations, including effects of disorder and conditions for zero-resistance states.

Findings

Quantum correction can produce zero-resistance states at high SAW amplitudes.

Resistivity oscillations are modulated at multiples of the cyclotron frequency.

Disorder type influences the nature of zero-resistance states.

Abstract

We study theoretically the geometrical and temporal commensurability oscillations induced in the resistivity of 2D electrons in a perpendicular magnetic field by surface acoustic waves (SAWs). We show that there is a positive anisotropic dynamical classical contribution and an isotropic non-equilibrium quantum contribution to the resistivity. We describe how the commensurability oscillations modulate the resonances in the SAW-induced resistivity at multiples of the cyclotron frequency. We study the effects of both short-range and long-range disorder on the resistivity corrections for both the classical and quantum non-equilibrium cases. We predict that the quantum correction will give rise to zero-resistance states with associated geometrical commensurability oscillations at large SAW amplitude for sufficiently large inelastic scattering times. These zero resistance states are qualitatively similar to those observed under microwave illumination, and their nature depends crucially on whether the disorder is short- or long-range. Finally, we discuss the implications of our results for current and future experiments on two dimensional electron gases.