Three reversible states controlled on a gold monoatomic contact by the electrochemical potential

TL;DR

This study demonstrates that the conductance of a gold monoatomic contact can be reversibly controlled among three distinct states by adjusting the electrochemical potential, with implications for nanoscale electronic devices.

Contribution

The paper introduces a method to reversibly switch the conductance states of a gold monoatomic contact using electrochemical potential control, revealing three distinct conductance regimes.

Findings

Conductance states at 1 G0, 0.5 G0, and below 1 G0 are controllably achieved.

Conductance states depend on electrochemical potential: -0.6 V, -1.0 V, and 0.8 V.

Proposed structural models explain conductance changes based on adsorbed hydrogen and oxygen incorporation.

Abstract

Conductance of an Au mono atomic contact was investigated under the electrochemical potential control. The Au contact showed three different behaviors depending on the potential: 1 $G_{0}$ ($G_{0}$ = $2e^{2}/h$), 0.5 $G_{0}$ and not-well defined values below 1 $G_{0}$ were shown when the potential of the contact was kept at -0.6 V (double layer potential), -1.0 V (hydrogen evolution potential), and 0.8 V (oxide formation potential) versus Ag/AgCl in 0.1 M Na$_{2}$SO$_{4}$ solution, respectively. These three reversible states and their respective conductances could be fully controlled by the electrochemical potential. These changes in the conductance values are discussed based on the proposed structure models of hydrogen adsorbed and oxygen incorporated on an Au mono atomic contact.