Measuring electron energy distribution by current fluctuations

A recent concept of local noise sensor is extended to measure the energy resolved electronic energy distribution f(ε) at a given location inside a non-equilibrium normal metal interconnect. A quantitative analysis of f(ε) is complicated because of a nonlinear differential resistance of the noise sensor, represented by a diffusive InAs nanowire. Nevertheless, by comparing the non-equilibrium results with reference equilibrium measurements, we conclude that f(ε) is indistinguishable from the Fermi distribution.