Theory of metastability in simple metal nanowires

TL;DR

This paper models thermally induced conductance jumps in metal nanowires using stochastic field theories, predicting nucleation processes, transition behaviors, and universal activation barriers related to surface tension.

Contribution

It introduces a stochastic Ginzburg-Landau model for nanowire conductance jumps, revealing universal activation barriers and transition behaviors dependent on wire length and strain.

Findings

Activation barriers are universal and proportional to the square root of surface tension.

Transition behavior depends on nanowire length, showing first- or second-order-like transitions.

Activation barrier decreases under strain.

Abstract

Thermally induced conductance jumps of metal nanowires are modeled using stochastic Ginzburg-Landau field theories. Changes in radius are predicted to occur via the nucleation of surface kinks at the wire ends, consistent with recent electron microscopy studies. The activation rate displays nontrivial dependence on nanowire length, and undergoes first- or second-order-like transitions as a function of length. The activation barriers of the most stable structures are predicted to be universal, i.e., independent of the radius of the wire, and proportional to the square root of the surface tension. The reduction of the activation barrier under strain is also determined.