Violation of Onsager symmetry for a ballistic channel Coulomb coupled to a quantum ring

TL;DR

This paper demonstrates that Coulomb interaction between a ballistic channel and a quantum ring causes asymmetric electron backscattering in a magnetic field, violating Onsager symmetry due to energy and angular momentum exchange.

Contribution

It provides an exact quantum mechanical analysis showing Onsager symmetry violation in a Coulomb-coupled system with a quantum ring.

Findings

Backscattering probability is asymmetric in magnetic field.

Energy and angular momentum are absorbed by the quantum ring.

Onsager symmetry is violated due to Coulomb interactions.

Abstract

We investigate a scattering of electron which is injected individually into an empty ballistic channel containing a cavity that is Coulomb coupled to a quantum ring charged with a single-electron. We solve the time-dependent Schr\"odinger equation for the electron pair with an exact account for the electron-electron correlation. Absorption of energy and angular momentum by the quantum ring is not an even function of the external magnetic field. As a consequence we find that the electron backscattering probability is asymmetric in the magnetic field and thus violates Onsager symmetry.