Weak dissipation does not result in disappearance of persistent current

TL;DR

Experimental evidence confirms that weak energy dissipation does not eliminate persistent currents in superconductor and normal metal rings, challenging the notion that dissipation necessarily destroys such quantum phenomena.

Contribution

The paper provides experimental validation that persistent currents persist despite weak dissipation, clarifying misconceptions about their dissipationless nature.

Findings

Persistent currents exist despite weak dissipation.

Dissipation does not lead to the disappearance of equilibrium currents.

Quantum oscillations in magnetic field relate to persistent currents.

Abstract

Experimental results obtained last years corroborate a prediction made by I.O. Kulik forty years ago that the energy dissipation does not result in disappearance of equilibrium circular current observable in the normal state of superconductor rings and normal metal rings. Contrary interpretations of the persistent current as a Brownian motion or a dissipationless current are compared in the point of view of the observations of this phenomenon at presence of an electric potential difference. Distinctions between the quantum phenomena at atomic and mesoscopic levels are accentuated. In connection of the quantum oscillations in magnetic field of potential difference observed on asymmetric rings with the persistent current, it is pointed out that an experimental check of such phenomenon at thermodynamic equilibrium is possible.