Interaction of a surface acoustic wave with a two-dimensional electron gas

TL;DR

This paper investigates how surface acoustic waves interact with a two-dimensional electron gas in GaAs, revealing that the coupling strength varies with propagation direction and is weakest along the [011] axis.

Contribution

It provides a calculation of the coupling coefficient for arbitrary propagation directions, highlighting directional dependence in SAW-electron interactions in GaAs.

Findings

Coupling strength depends significantly on propagation direction.

Weakest coupling occurs along the [011] direction.

Coupling coefficient can be calculated for any propagation direction.

Abstract

When a surface acoustic wave propagates on the surface of a GaAs semiconductor, coupling between electrons in the two-dimensional electron gas beneath the interface and the elastic host crystal through piezoelectric interaction will attenuate the SAW. The coupling coefficient is calculated for the SAW propagating along an arbitrary direction. It is found that the coupling strength is largely dependent on the propagating direction. When the SAW propagates along the [011] direction, the coupling becomes quite weak.