Two-copy Quantum Teleportation

TL;DR

This paper explores a two-copy quantum teleportation protocol, deriving the optimal teleportation fidelity based on a new entanglement measure, and demonstrating its superiority over single-copy teleportation.

Contribution

The paper introduces a detailed two-copy teleportation protocol and derives the optimal fidelity expression using the two-copy fully entangled fraction, highlighting improvements over traditional methods.

Findings

Optimal teleportation fidelity is derived and expressed via the two-copy fully entangled fraction.

States with a bounded two-copy fully entangled fraction form a convex, compact set, enabling witness operators.

Two-copy teleportation fidelity exceeds that of single-copy teleportation.

Abstract

We investigate two-copy scenario of quantum teleportation based on Bell measurements. The detailed protocol is presented and the general expression of the corresponding optimal teleportation delity is derived, which is given by the two-copy fully entangled fraction that is invariant under local unitary transformations. We prove that under a speci c case of the protocol, which is signi cant for improving the optimal delity, the set of states with their two-copy fully entangled fractions bounded by a threshold value that required for useful two-copy teleportation is convex and compact. Hence the witness operators exist to separate states that are useful for two-copy teleportation from the rest ones. Moreover, we show that the optimal delity of two-copy teleportation surpasses that of the original one copy teleportation.