Piezoelectric electromechanical coupling in nanomechanical resonators with two-dimensional electron gas

TL;DR

This paper investigates how nanomechanical vibrations influence the electrical conductivity of a two-dimensional electron gas, revealing a piezoelectric effect driven by boundary stress changes.

Contribution

It provides the first experimental demonstration and physical model of piezoelectric electromechanical coupling in nanomechanical resonators with 2D electron gas.

Findings

Vibrations cause opposite conductivity changes near cantilever bases.

The main conductivity change stems from boundary stress variations.

The physical model accurately explains experimental results.

Abstract

The electrical response of two-dimensional electron gas to vibrations of a nanomechanical cantilever containing it is studied. Vibrations of perpendicularly oriented cantilevers are experimentally shown to change oppositely the conductivity near their bases. This indicates the piezoelectric nature of electromechanical coupling. A physical model is developed, which quantitatively explains the experiment. It shows that the main origin of the conductivity change is a rapid change in the mechanical stress on the boundary between suspended and non-suspended areas, rather than the stress itself.