Semi-classical understanding of flux quantization in superconductors

TL;DR

This paper offers a semi-classical explanation for the flux quantum in superconductors, linking it to the Aharonov-Bohm effect's nonlocality, and clarifies why the flux quantum differs in the quantum Hall effect.

Contribution

It introduces a novel semi-classical framework connecting flux quantization in superconductors to the Aharonov-Bohm effect's nonlocality, explaining the h/2e flux quantum.

Findings

Flux quantum in superconductors is h/2e due to nonlocality effects.

The flux quantum in the quantum Hall effect is h/e, consistent with theoretical predictions.

Provides a unified semi-classical explanation for flux quantization phenomena.

Abstract

Like electric charge, magnetic flux is also quantised. Theoretically, one can show that the flux quantum must be h/e, as observed in the quantum Hall effect. However, in the superconducting systems, the flux quantum is experimentally observed as h/2e. There is no fundamental explanation for the empirical result. In this article, we argue that this phenomenon is fundamentally linked to the nonlocality problem of the Aharonov-Bohm effect and present a new semi-classical explanation for the magnetic flux quantum in superconductivity. This work will also show why the flux quantum should be h/e in the case of the quantum Hall effect.