PHASE-SENSITIVE REENTRANCE INTO THE NORMAL-STATE OF MESOSCOPIC SNS STRUCTURES

Normal (N) metallic (Ag) mesoscopic conductors with two superconductin g (S) faces (Al), arranged mirror-symmetrically relative to the stream lines of the current, periodically switch into the normal state as the superconducting phase difference Delta phi between the NS boundaries approaches the values Delta phi = (2n + 1)pi, n = 0,1,2,..., irrespect ive of temperature and applied voltage. For Delta phi = 2n pi and low applied voltages the conductance passes through a maximum and approach es the normal value as temperature decreases (reentrance). As the volt age subsequently increases, the conductance increases and passes throu gh a maximum. As the phase difference moves away from the values Delta phi = 2n pi, the maxima shift in the direction of low temperatures an d voltages. The latter result shows unequivocally that in our metal st ructures it is necessary to take into account the next-order correctio ns to the ''weak'' proximity effect approximation. (C) 1998 American I nstitute of Physics.