On Extension of Optimal Entanglement Concentration of GHZ States in Quantum-Dot and Micro-Cavity Coupled System

We extend an optimal entanglement distillation of the triplet Greenberger–Horne–Zeilinger(GHZ) state via entanglement concentrating in the three-partite partially electron-spin-entangled systems. Two entanglement concentration protocols are similarly designed in detail with the post-selection in quantum-dot(QD) and micro-cavity coupled systems. The proposed protocol can be repeated several rounds to achieve an optimal success probability with an assistance of the ancillary QD, where only the single photon needs to pass through the micro-cavity for each round. It increases the total success probability of the distillation even if the implemented cavity is imperfect in practice during the whole process.