Theoretical Fluctuations of Conductance in Stretched Monatomic Nanowire

TL;DR

This paper explains conductance fluctuations in stretched monatomic gold nanowires through simulations showing how bond length variations affect electronic conductance, matching experimental observations.

Contribution

It introduces a theoretical model linking bond length distributions to conductance fluctuations in nanowires, providing insight into experimental phenomena.

Findings

Bond length inhomogeneity causes conductance fluctuations.

Simulations reproduce the 5% fluctuation magnitude.

Distribution of bond lengths explains experimental results.

Abstract

Recent experiments showed that the last, single channel conductance step in monatomic gold contacts exhibits significant fluctuations as a function of stretching. From simulations of a stretched gold nanowire linked to deformable tips, we determine the distribution of the bond lengths between atoms forming the nanocontact and analyze its influence on the electronic conductance within a simplified single channel approach. We show that the inhomogeneous distribution of bond lengths can explain the occurrence and the 5% magnitude of conductance fluctuations below the quantum conductance unit $g_{o}= 2e^2/h$.