How Large is the Intrinsic Flux Noise of a Magnetic Flux Quantum, of Half a Flux Quantum and of a Vortex-Free Superconductor?

TL;DR

This paper investigates the intrinsic flux noise in superconductors, finding that stationary vortices do not significantly increase noise, while half flux quanta in $$-rings exhibit notably higher noise levels.

Contribution

It provides a quantitative analysis of flux noise in different superconducting states, highlighting the noise characteristics of half flux quanta in $$-rings.

Findings

Stationary vortices do not significantly enhance flux noise.

Half flux quanta in $$-rings have substantially larger noise.

Intrinsic flux noise in superconductors is generally low.

Abstract

This article addresses the question whether the magnetic flux of stationary vortices or of half flux quanta generated by frustrated superconducting rings is noisy. It is found that the flux noise generated intrinsically by a superconductor is, in good approximation, not enhanced by stationary vortices. Half flux quanta generated by $\pi$-rings are characterized by considerably larger noise.