PHASE COHERENCE IN A 2-DIMENSIONAL ARRAY OF NORMAL AND SUPERCONDUCTING WIRES

We present a study of a two-dimensional superconducting network made of perpendicular normal (N) and superconducting (S) wires. A two-axes angle evaporation technique has been developed in an ultrahigh vacuum system, in order to control efficiently the quality of the N-S interface. Below the superconducting transition of S, the strong anisotropy of the system induces a localization of the superconducting order parameter along the S wires. The study of the electron transport along the N wires as a function of temperature and magnetic field gives physical insight in a regime of high anisotropy in superconducting arrays. In the direction of the N wires, the proximity effect induces a resistive transition at low temperature. This system has an original magnetoresistance signature, related to interference effects between proximity-induced superconducting currents. © 1995 The American Physical Society.