Entanglement thresholds for displaying the quantum nature of teleportation

A protocol for transferring an unknown single qubit state evidences quantum features when the average fidelity of the outcomes is, in principle, greater than 2/3. We propose to use the probabilistic and unambiguous state extraction scheme as a mechanism to redistribute the fidelity in the outcome of the standard teleportation when the process is performed with an X-state as a noisy quantum channel. We show that the entanglement of the channel is necessary-but not sufficient in order for the average fidelity f(x) to display quantum features, i.e., we find a threshold C-X for the concurrence of the channel. On the other hand, if the mechanism for redistributing fidelity is successful then we find a filterable outcome with average fidelity f(X,0) that can be greater than f(X). In addition, we find the threshold concurrence of the channel C-X,C-0 in order for the average fidelity f(X,0) to display quantum features and surprisingly, the threshold concurrence C-X,C-0 can be less than C-X. Even more, we find some special cases for which the threshold values become zero. (C) 2016 Elsevier Inc. All rights reserved.