Novel Aharonov-Bohm-like effect: Detectability of the vector potential in a solenoidal configuration with a ferromagnetic core covered by superconducting lead, and surrounded by a thin cylindrical shell of aluminum

TL;DR

This paper demonstrates a macroscopic Aharonov-Bohm-like effect where a ferromagnetic core influences a SQUID-like device via the vector potential, despite magnetic shielding, revealing new quantum-mechanical effects in superconducting systems.

Contribution

It introduces a novel experimental setup showing the detectability of the vector potential in a superconducting configuration with magnetic shielding, expanding understanding of quantum effects in macroscopic systems.

Findings

Detection of vector potential via Josephson effect in SQUID-like device

Observation of asymmetric hysteresis loop indicating Aharonov-Bohm-like effect

Demonstration of magnetic field shielding with measurable quantum influence

Abstract

The flux as measured by the Josephson effect in a SQUID-like configuration with a ferromagnetic core inserted into its center, is shown to be sensitive to the vector potential arising from the central ferromagnetic core, even when the core is covered with a superconducting material that prevents any magnetic field lines from ever reaching the perimeter of the SQUID-like configuration. This leads to a macroscopic, Aharonov-Bohm-like effect that is observable in an asymmetric hysteresis loop in the response of the SQUID-like configuration to an externally applied magnetic field.