Influence of a new energy scale on conductance fluctuations and weak localization in ultrasmall metallic nanobridges

Abstract

Conductance fluctuations and weak localization in ultrasmall gold bridges with all dimensions smaller than the elastic mean free path have been studied as a function of magnetic field and applied bias voltage. In addition to the well known Thouless energy we observe a new energy scale in the dependence of both quantum interference effects on the bias voltage. This new energy scale agrees well with the level separation estimated for the states in the corresponding closed system.