Shot noise suppression at room temperature in atomic-scale Au junctions

TL;DR

This study demonstrates quantum shot noise suppression at room temperature in atomic-scale gold junctions using high-frequency measurements, revealing quantum transport behavior under ambient conditions.

Contribution

First room-temperature measurement of shot noise suppression in atomic gold junctions using a high-frequency technique, confirming quantum transport at ambient conditions.

Findings

Shot noise suppression observed at up to three conductance quanta.

Indications of local heating and 1/f noise at high biases.

Quantum transport behavior confirmed at room temperature.

Abstract

Shot noise encodes additional information not directly inferable from simple electronic transport measurements. Previous measurements in atomic-scale metal junctions at cryogenic temperatures have shown suppression of the shot noise at particular conductance values. This suppression demonstrates that transport in these structures proceeds via discrete quantum channels. Using a high frequency technique, we simultaneously acquire noise data and conductance histograms in Au junctions at room temperature and ambient conditions. We observe noise suppression at up to three conductance quanta, with possible indications of current-induced local heating and $1/f$ noise in the contact region at high biases. These measurements demonstrate the quantum character of transport at room temperature at the atomic scale. This technique provides an additional tool for studying dissipation and correlations in nanodevices.