Incompatibility of optimized protection of entanglement and teleportation fdelity in the presence of decoherence

Abstract

Entanglement is the key success of teleporting an unknown quantum state with fidelity higher than classical limit. In the presence of decoherence, entanglement decreases with the strength of interaction between quantum systems and the environment. As a result, teleportation fidelity (TF) decreases. The technique of weak measurement and its reversal help to protect entanglement in the presence of amplitude-damping decoherence. In this work, we have shown that the optimal protection of entanglement does not optimize TF. More specifically, when one of the systems interacts with the environment, optimized TF requires higher strength of reverse weak measurement than optimized entanglement protection. The success probability of optimal protection indicates that higher form of nonlocal correlation plays the key role in optimizing TF. Interestingly, when both systems interact with the environment, optimization of entanglement implies optimization of TF. Therefore, the resources of quantum teleportation along with entanglement need to be explored.