Multiphoton-state-assisted entanglement purification of material qubits

TL;DR

This paper introduces a novel entanglement purification protocol using material qubits and multiphoton states, leveraging current experimental setups to produce high-fidelity entangled pairs efficiently.

Contribution

It presents a new purification scheme combining material qubits with multiphoton states and postselective homodyne detection, enabling high-fidelity entanglement with existing technology.

Findings

Probabilistic quantum operation successfully used for purification

High-fidelity entangled pairs achieved at high repetition rates

Scheme compatible with current experimental setups

Abstract

We propose an entanglement purification scheme based on material qubits and ancillary coherent multiphoton states. We consider a typical QED scenario where material qubits implemented by two-level atoms fly sequentially through a cavity and interact resonantly with a single mode of the radiation field. We explore the theoretical possibilities of realizing a high-fidelity two-qubit quantum operation necessary for the purification protocol with the help of a postselective balanced homodyne photodetection. We demonstrate that the obtained probabilistic quantum operation can be used as a bilateral operation in the proposed purification scheme. It is shown that the probabilistic nature of this quantum operation is counterbalanced in the last step of the scheme where qubits are not discarded after inadequate qubit measurements. As this protocol requires present-day experimental setups and generates high-fidelity entangled pairs with high repetition rates, it may offer interesting perspectives for applications in quantum information theory.