Electronic state back action on mechanical motion in a quantum point contact coupled to a nanomechanical resonator

TL;DR

This paper investigates how the electronic state in a quantum point contact influences the mechanical motion of a coupled nanomechanical resonator, revealing correlations between conductance and resonator frequency.

Contribution

It introduces a model explaining frequency deviations based on the quantum point contact's screening ability of piezoelectric charge, linking electronic and mechanical properties.

Findings

Conductance varies with subband index and correlates with resonator frequency.

Frequency deviations are explained by the screening ability of the quantum point contact.

Potential for electromechanical methods to study density of states in 1D systems.

Abstract

In a nanomechanical resonator coupled to a quantum point contact, the back action of the electronic state on mechanical motion is studied. The quantum point contact conductance changing with subband index and the eigenfrequency of the resonator are found to correlate. A model is constructed explaining the frequency deviations by the alternating ability of the quantum point contact to screen the piezoelectric charge induced by mechanical oscillations. The observed effects can be used to develop electromechanical methods for studying the density of states in quasi-one-dimensional systems.