Shot-noise spectroscopy of energy-resolved ballistic currents

TL;DR

This paper demonstrates that shot-noise measurements in ballistic conductors with Coulomb interactions can reveal detailed energy profiles of injected electrons, providing insights unattainable through average current measurements alone.

Contribution

It introduces a method to analyze energy-resolved electron profiles via shot-noise in the presence of Coulomb interactions, highlighting the role of potential barrier fluctuations.

Findings

Coulomb interactions enable energy analysis of injected electrons.

Shot-noise fluctuations reveal energy profile details.

Average quantities do not provide the same information.

Abstract

We investigate the shot noise of nonequilibrium carriers injected into a ballistic conductor and interacting via long-range Coulomb forces. Coulomb interactions are shown to act as an energy analyzer of the profile of injected electrons by means of the fluctuations of the potential barrier at the emitter contact. We show that the details in the energy profile can be extracted from shot-noise measurements in the Coulomb interaction regime, but cannot be obtained from time-averaged quantities or shot-noise measurements in the absence of interactions.