Free-electron Model for Mesoscopic Force Fluctuations in Nanowires

TL;DR

This paper presents a free-electron model to explain mesoscopic force fluctuations in nanowires, showing that electronic effects can account for observed force variations of about 2 nN during wire separation.

Contribution

It introduces a simple free-electron model for nanowire force fluctuations, linking electronic contributions to experimentally observed force variations.

Findings

Electronic contribution to force fluctuations is about 2 nN.

The model explains quantized conductance and force fluctuations during nanowire separation.

Force fluctuations are comparable to experimental measurements.

Abstract

When two metal electrodes are separated, a nanometer sized wire (nanowire) is formed just before the contact breaks. The electrical conduction measured during this retraction process shows signs of quantized conductance in units of G_0=2e^2/h. Recent experiments show that the force acting on the wire during separation fluctuates, which has been interpreted as being due to atomic rearrangements. In this report we use a simple free electron model, for two simple geometries, and show that the electronic contribution to the force fluctuations is comparable to the experimentally found values, about 2 nN.