Two-partite entanglement purification assisted by quantum-dot spins inside single-sided optical microcavities

Entanglement purification is an important and useful tool in quantum communications that allows parties to enhance the entanglement of a set of less-entangled particles using local operations and classical communication. Utilizing photon polarization parity checks implemented through the coupling system between a single-sided cavity and a charged quantum dot, an entanglement purification scheme is proposed in this paper. The fidelity and the success probability of the scheme are calculated under bit-flip error channel and depolarizing channel, respectively. Furthermore, the impact of imperfect quantum-dot-cavity coupling system is investigated, and the feasibility is discussed. In the strong coupling and weak cavity side leakage regime, our scheme can approach the maximal fidelities and success probabilities in theory. So the scheme has potential applications in long-distance quantum communication with the development of relevant technologies.