Electrolyte gating of gold point contacts

Gold point contacts are fabricated in-situ by electromigration in an ionic liquid bath. These contacts are shown to be stable at room temperature at conductances as small as 50 G$_0$. By electrolyte gating the contacts using a counter electrode in the ionic liquid, conductance changes of 25$\%$ are observed, corresponding to accumulation of more than one electron per gold surface atom. Double step chronocoulometry and x-ray reflectometry suggest that ion ordering in the ionic liquid near the gold interface are consistent with the observed changes in conductance.