Excess noise in STM-style break junctions at room temperature

摘要: Current noise in nanoscale systems provides additional information beyond the electronic conductance. We report measurements at room temperature of nonequilibrium ``excess'' ensembles atomic-scale gold junctions repeatedly formed and broken between a tip film, as function bias conditions. observe suppression near conductances associated with conductance quantization such junctions, expected from finite theory shot limit few quantum channels. In higher Fano factor approaches 1/3 value seen low tunneling limit, consistent theoretical expectations for approach to diffusive regime. At values where is comparatively suppressed, there residual contribution that scales quadratically applied bias, likely due flicker noise/conductance fluctuation mechanism.