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

摘要

Shot noise encodes additional information not directly inferable from simpleelectronic transport measurements. Previous measurements in atomic-scale metaljunctions at cryogenic temperatures have shown suppression of the shot noise atparticular conductance values. This suppression demonstrates that transport inthese structures proceeds via discrete quantum channels. Using a high frequencytechnique, we simultaneously acquire noise data and conductance histograms inAu junctions at room temperature and ambient conditions. We observe noisesuppression at up to three conductance quanta, with possible indications ofcurrent-induced local heating and $1/f$ noise in the contact region at highbiases. These measurements demonstrate the quantum character of transport atroom temperature at the atomic scale. This technique provides an additionaltool for studying dissipation and correlations in nanodevices.