Using quantum routers to implement quantum message authentication and Bell-state manipulation

In this paper we investigate the capability of quantum routing (quantum state fusion) to implement two useful quantum communications protocols. The analyzed protocols include quantum authentication of quantum messages and non-destructive linear-optical Bell state manipulation. We also present the concept of quantum decoupler -- a device implementing an inverse operation to quantum routing. We demonstrate that both quantum router and decoupler can work as specialized disentangling gates.