Jahn-Teller Distortions and the Supershell Effect in Metal Nanowires

D. F. Urban, J. Bürki, C. -H. Zhang, C. A. Stafford, Hermann Grabert

Published 2003-12-19, updated 2004-10-29Version 2

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.