Persistent current induced by vacuum fluctuations in a quantum ring

TL;DR

This paper theoretically demonstrates that vacuum electromagnetic fluctuations can induce a persistent current in a quantum ring, creating a magnetic moment without dissipation, effectively acting as an artificial spin.

Contribution

It introduces a novel mechanism where vacuum fluctuations cause persistent currents in quantum rings, linking quantum electrodynamics with mesoscopic electron transport.

Findings

Vacuum fluctuations split electron states with opposite angular momenta.

Ground state can host a nonzero electric current.

Quantum ring exhibits a magnetic moment due to vacuum-induced current.

Abstract

We study theoretically interaction between electrons in a quantum ring embedded in a microcavity and vacuum fluctuations of electromagnetic field in the cavity. It is shown that the vacuum fluctuations can split electron states of the ring with opposite angular momenta. As a consequence, the ground state of electron system in the quantum ring can be associated to nonzero electric current. Since a ground-state current flows without dissipation, such a quantum ring gets a magnetic moment and can be treated as an artificial spin.