Deterministic Teleportation and Universal Computation Without Particle Exchange

Teleportation is a cornerstone of quantum technologies, and has played a key role in the development of quantum information theory. Pushing the limits of teleportation is therefore of particular importance. Here, we apply a different aspect of quantumness to teleportation -- namely exchange-free computation at a distance. The controlled-phase universal gate we propose, where no particles are exchanged between control and target, allows complete Bell detection among two remote parties, and is experimentally feasible. Our teleportation-with-a-twist, which we extend to telecloning, then requires no pre-shared entanglement nor classical communication between sender and receiver, with the teleported state gradually appearing at its destination.
Comment: 18 pages, 5 figures; reference data fixed