Single-channel transmission in gold one-atom contacts and chains

TL;DR

This study investigates superconductivity in gold atomic contacts and wires, revealing that typically only one conduction channel is nearly fully open, using STM fabrication and analysis of non-linear I(V) characteristics.

Contribution

It demonstrates the presence of a single dominant conduction channel in gold atomic contacts and wires, confirmed through experimental analysis and theoretical agreement.

Findings

Only one conduction channel is nearly fully open.

Superconductivity induced by proximity effect in gold structures.

Analysis of I(V) curves reveals transmission probabilities.

Abstract

We induce superconductivity by proximity effect in thin layers of gold and study the number of conduction channels which contribute to the current in one-atom contacts and atomic wires. The atomic contacts and wires are fabricated with a Scanning Tunneling Microscope. The set of transmission probabilities of the conduction channels is obtained from the analysis of the $I(V)$ characteristic curve which is highly non-linear due to multiple Andreev reflections. In agreement with theoretical calculations we find that there is only one channel which is almost completely open.