Multiport based teleportation -- protocol and its performance

Piotr Kopszak, Marek Mozrzymas, Michał Studziński, Michał Horodecki

Published 2020-08-03Version 1

We propose a novel multi-port teleportation scheme performing transmission of a number of unknown quantum states or one composite system in one go. Teleported states arrive on several ports on the receiver's side. Using equivalence between the teleportation process and state discrimination task we derive a lower bound on the performance of the protocol, measured in the entanglement fidelity. Obtained bound is effective, in the sense it depends only on the global parameters like the number of teleported states, the number of ports, and the dimension of the underlying Hilbert space. The lower bound outperform the explicit values of the entanglement fidelity calculated for the non- and optimal port-based teleportation with the minimal possible dimension of the port. We show that the number of teleported systems can grow when the number $N$ of ports increases. We further obtain that maximal number of faithfully teleported systems differs qualitatively in deterministic and probabilistic scheme: it scales as $o(N)$ and $o(\sqrt{N})$ respectively. In the end, we deliver closed-form expressions for the entanglement fidelity as well as for the probability of success in the qubit case in the picture of the spin angular momentum.