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
  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. 
R. Y. Chiao
quant-ph