Influence of the in-plane magnetic field on the Andreev conductance of a superconductor-insulator-normal metal structure

Pronounced conductance due to electrons experiencing Andreev reflection from a superconducting condensate has been observed in superconductor (aluminum)-insulator (aluminum oxide)-normal metal (copper) tunnel junctions at low voltages, along with single-electron tunneling. It has been discovered experimentally that the collective current is suppressed in the magnetic field parallel to the tunnel junction plane and the Andreev conductance decreases nearly twofold in a field of $\sim20$–$30$ mT.