Suppression and enhancement of the critical current in multiterminal superconductor-normal-metal-superconductor mesoscopic structures

We analyze the measured critical current I-m in a mesoscopic four-terminal superconductor-normal-metalsuperconductor (S/N/S) structure. The current th rough the S/N interface is shown to consist not only of the Josephson compo nent I-c sin phi, but also a phase-coherent part I-sg cos phi of the subgap current. The current I-m is determined by both components I-c and I-sg, an d depends in a nonmonotonic way on the voltage V between superconductors an d normal reservoirs reaching a maximum at V congruent to Delta/e. The obtai ned theoretical results are in qualitative agreement with recent experiment al data.