Nanowire Gold Chains: Formation Mechanisms and Conductance

TL;DR

This paper uses ab initio simulations to study the formation, structure, and conductance of gold nanowires, revealing how strain induces structural transformations and affects electronic transport properties.

Contribution

It provides detailed insights into the atomic configurations and conductance behavior of gold nanowires during elongation, combining simulations with experimental correlation.

Findings

Double-strand wire yields a bent-chain structure under strain.

Conductance drops from near 2g_0 to 1g_0 during transformation.

Stable 1g_0 conductance plateau persists over extended elongation.

Abstract

Structural transformations, electronic spectra and ballistic transport in pulled gold nanowires are investigated with ab initio simulations, and correlated with recent measurements. Strain-induced yield of an initial double-strand wire results first in formation of a bent-chain which transforms upon further elongation to a linear atomic chain exhibiting dimerized atomic configurations. These structures are stabilized by directional local bonding with spd-hybridization. The conductance of the initial double-stranded contact is close to 2g_0 and it drops sharply to 1g_0 during the transformation to a single chain, exhibiting subsequently a 1g_0 plateau extending over an elongation well above typical Au-Au distances.