Phonon-induced resistance oscillations of two-dimensional electron systems drifting with supersonic velocities

TL;DR

This paper develops a theory explaining phonon-assisted nonlinear resistivity oscillations in 2D electron systems under high magnetic fields, revealing a phase change at the sound barrier and contrasting behaviors in subsonic and supersonic regimes.

Contribution

The paper introduces a comprehensive theoretical model for phonon-induced resistance oscillations in 2D electron systems, including the phase change at the sound barrier and temperature-dependent behaviors.

Findings

Quantitative match with experimental oscillation patterns in the subsonic regime

Identification of a $$ phase shift across the sound barrier

Saturation of oscillation amplitude in the supersonic regime at low temperatures

Abstract

We present a theory of the phonon-assisted nonlinear dc transport of 2D electrons in high Landau levels. The nonlinear dissipative resistivity displays quantum magneto-oscillations governed by two parameters which are proportional to the Hall drift velocity $v_H$ of electrons in electric field and the speed of sound $s$. In the subsonic regime, $v_H<s$, the theory quantitatively reproduces the oscillation pattern observed in recent experiments. We also find the $\pi/2$ phase change of oscillations across the sound barrier $v_H=s$. In the supersonic regime, $v_H>s$, the amplitude of oscillations saturates with lowering temperature, while the subsonic region displays exponential suppression of the phonon-assisted oscillations with temperature.