Trapping $\tfrac{h}{2e}$ Flux in Metals

TL;DR

This paper uncovers a novel flux quantization phenomenon in metals, showing they trap either zero or half of the flux quantum due to backreaction effects, with analytical and experimental insights into the process.

Contribution

It introduces a new flux trapping effect in metals, demonstrating the trapping of half flux quantum and analyzing the persistent currents as the flux source is removed.

Findings

Metals can trap 0 or h/2e flux due to backreaction effects.

Analytical demonstration of flux trapping in metals wrapping a solenoid.

Persistent localized currents reflect perfect defect-diamagnetism of the Fermi gas.

Abstract

We report on a new flux quantization phenomenon in metals. We study the response of normal metals to the presence of localized magnetic flux. We find that, due to backreaction effects, the metal traps 0 flux or $\tfrac{h}{2e}$ flux (half flux). We exhibit this effect both for metals pierced by magnetic solenoids and metals wrapping a magnetic solenoid. In the latter case we demonstrate the trapping of magnetic flux analytically. Furthermore, we find that as the solenoid is adiabatically turned off, a logarithmically enhanced localized equilibrium current persists, reflecting perfect defect-diamagnetism of the Fermi gas.