Jahn-Teller Distortions and the Supershell Effect in Metal Nanowires

TL;DR

This paper investigates how Jahn-Teller distortions influence the stability and structure of metal nanowires, revealing stable elliptic forms and explaining experimental conductance patterns, with predictions for gold and superdeformed states.

Contribution

It introduces the concept that Jahn-Teller deformations can stabilize elliptic nanowires, providing a new interpretation of conductance histograms and predicting superdeformed nanowires.

Findings

Elliptic nanowires can be energetically favorable due to Jahn-Teller effects.

Stable sequences of cylindrical and elliptical nanowires explain experimental conductance data.

Elliptic nanowires are more likely in gold due to smaller eccentricity.

Abstract

A stability analysis of metal nanowires shows that a Jahn-Teller deformation breaking cylindrical symmetry can be energetically favorable, leading to stable nanowires with elliptic cross sections. The sequence of stable cylindrical and elliptical nanowires allows for a consistent interpretation of experimental conductance histograms for alkali metals, including both the shell and supershell structures. It is predicted that for gold, elliptical nanowires are even more likely to form since their eccentricity is smaller than for alkali metals. The existence of certain metastable ``superdeformed'' nanowires is also predicted.