Quantum teleportation via maximum-confidence quantum measurements

TL;DR

This paper explores an optimized quantum teleportation method using maximum-confidence measurements, achieving higher fidelity and success probability for certain quantum channels compared to standard protocols.

Contribution

It introduces a maximum-confidence measurement approach for teleporting unknown qudit states, surpassing traditional fidelity limits and enabling sequential measurements for improved success rates.

Findings

Maximum-confidence measurements improve teleportation fidelity.

Sequential measurements can further enhance success probability.

Fidelity depends only on the Schmidt rank of the channel.

Abstract

We investigate the problem of teleporting unknown qudit states via pure quantum channels with nonmaximal Schmidt rank. This process is mapped to the problem of discriminating among nonorthogonal symmetric states which are linearly dependent and equally likely. It is shown that by applying an optimized maximum-confidence (MC) measurement for accomplishing this task, one reaches the maximum possible teleportation fidelity after a conclusive event in the discrimination process, which in turn occurs with the maximum success probability. In this case, such fidelity depends only on the Schmidt rank of the channel and it is larger than the optimal one achieved, deterministically, by the standard teleportation protocol. Furthermore, we show that there are quantum channels for which it is possible to apply a k-stage sequential MC measurement in the discrimination process such that a conclusive event at any stage leads to a teleportation fidelity above the aforementioned optimal one and, consequently, increases the overall success probability of teleportation with a fidelity above this limit.