2 4 A ug 2 00 3 Proximity effect in superconductor Aharonov Bohm loop hybrid structures

We study the proximity effect in superconductor-metallic or ferromagnetic Aharonov Bohm loop hybrid structures self consistently using the Bogoliubov-deGennes formalism within the two dimensional extended Hubbard model. We calculate the local density of states, the pair amplitude, and persistent currents as a function of several modulation parameters, the position around the loop, the exchange field, the magnetic flux through the loop, the loop size, and the chemical potential in the loop atoms. We find that the parameters above can modulate the proximity effect.