Low temperature electron-phonon resonance in dc-current-biased two-dimensional electron systems

TL;DR

This paper investigates how resonant acoustic phonon scattering affects magnetoresistivity in low-temperature two-dimensional electron systems, revealing that electron drift velocity influences phonon resonance peaks and nonlinear transport phenomena.

Contribution

It demonstrates that bulk phonon modes cause observed resonances without leaky phonons and shows how finite bias current enhances these effects through electron heating.

Findings

Resonances originate from bulk phonons in GaAs systems.

Finite bias current amplifies phonon resonances via electron heating.

High electron drift velocity leads to additional resonance peaks and negative differential resistivity.

Abstract

Effects of resonant acoustic phonon scattering on magnetoresistivity are examined in two-dimensional electron systems at low temperatures by using a balance-equation magnetotransport scheme direct controlled by the current. The experimentally observed resonances in linear resistivity are shown to result from the conventional bulk phonon modes in a GaAs-based system, without invoking leaky interface phonons. Due to quick heating of electrons, phonon resonances can be dramatically enhanced by a finite bias current. When the electron drift velocity increases to the speed of sound, additional and prominent phonon resonance peaks begin to emerge. As a result, remarkable resistance oscillation and negative differential resistivity can appear in nonlinear transport in a modest mobility sample at low temperatures, which is in agreement with recent experiments.