Heat and charge transport measurements to access single-electron quantum characteristics

TL;DR

This paper explores how electrical and heat currents in mesoscopic systems reveal the quantum characteristics of single-electron states, providing methods to reconstruct wave functions and analyze shot noise behavior.

Contribution

It introduces a novel interpretation of single-particle heat current and demonstrates how combined electrical and heat current measurements enable full wave function reconstruction.

Findings

Heat shot noise relates to charge shot noise when only one stream is present.

Full wave function reconstruction is possible from time-dependent electrical and heat currents.

Heat and charge shot noise behaviors differ when two electronic streams collide.

Abstract

In the framework of the Floquet scattering-matrix theory we discuss how electrical and heat currents accessible in mesoscopics are related to the state of excitations injected by a single-electron source into an electron waveguide. We put forward an interpretation of a single-particle heat current, which differs essentially from that of an electrical current. We show that the knowledge of both a time-dependent electrical current and a time-dependent heat current allows the full reconstruction of a single-electron wave function. In addition we compare electrical and heat shot noise caused by splitting of a regular stream of single-electron excitations. If only one stream impinges on a wave splitter, the heat shot noise is proportional to the well-known expression of the charge shot noise, reflecting the partitioning of the incoming single particles. The situation differs when two electronic streams collide at the wave splitter. The shot noise suppression, due to the Pauli exclusion principle, is governed by different overlap integrals in the case of charge and of heat.