TRANSPORT IN MULTITERMINAL NORMAL-SUPERCONDUCTOR DEVICES - RECIPROCITY RELATIONS, NEGATIVE AND NONLOCAL RESISTANCES, AND REENTRANCE OF THE PROXIMITY EFFECT

We have investigated transport in a cross-shaped two-dimensional elect ron gas with superconducting electrodes coupled to two opposite arms. Multiterminal resistances, measured as a function of the superconducti ng phase difference and the magnetic flux, are analyzed in terms of an extended Landauer-Buttiker transport formalism. We show that extended reciprocity relations hold. Correlations between transport coefficien ts are obtained from, e.g., (negative) three-terminal and nonlocal res istances. Energy spectroscopy reveals a reentrant behavior of the tran sport coefficients around the Thouless energy.