Increasing singlet fraction with entanglement swapping

TL;DR

This paper demonstrates that entanglement swapping can increase the singlet fraction and teleportation fidelity of mixed quantum states, with practical implementation via linear optics.

Contribution

It shows that entanglement swapping can enhance singlet fraction and teleportation fidelity for mixed states, a novel application in quantum communication.

Findings

Entanglement swapping increases singlet fraction in certain mixed states.

Entanglement swapping can improve teleportation fidelity.

The effect can be demonstrated using linear optical setups.

Abstract

We consider entanglement swapping for certain mixed states. We assume that the initial states have the same singlet fraction and show that the final state can have singlet fraction greater than the initial states. We also consider two quantum teleportations and show that entanglement swapping can increase teleportation fidelity. Finally, we show how this effect can be demonstrated with linear optics.