Teleportation in the presence of common bath decoherence at the transmitting station

TL;DR

This paper studies how common bath decoherence affects quantum teleportation fidelity, revealing that the type of Bell measurement and qubit-bath interactions significantly influence teleportation success.

Contribution

It provides a generalized density matrix framework for teleportation under common bath decoherence and analyzes the impact of different Bell measurements and entangled states.

Findings

High fidelity with singlet measurement under ferromagnetic or antiferromagnetic interactions.

Triplet measurements yield better fidelity when qubits have mixed interactions.

Non-maximally entangled basis can optimize teleportation fidelity.

Abstract

We investigate the effect of common bath decoherence on the qubits of Alice in the usual teleportation protocol. The system bath interaction is studied under the central spin model, where the qubits are coupled to the bath spins through isotropic Heisenberg interaction. We have given a more generalized representation of the protocol in terms of density matrices and calculated the average fidelity of the teleported state for different Bell state measurements performed by Alice. The common bath interaction differentiates the outcome of various Bell state measurements made by Alice. There will be a high fidelity teleportation for a singlet measurement made by Alice when both the qubits of Alice interact either ferromagnetically or antiferromagnetically with bath. In contrast if one of the Alice's qubits interact ferromagnetically and the other anti-ferromagnetically then measurement of Bell states belonging to the triplet sector will give better fidelity. We have also evaluated the average fidelity when Alice prefers non-maximally entangled states as her basis for measurement.