Efficient entanglement concentration for arbitrary less-entangled N-atom state

TL;DR

This paper presents an improved entanglement concentration protocol for arbitrary less-entangled N-atom GHZ states, requiring fewer resources and offering higher success probability, making it more practical for quantum information processing.

Contribution

It introduces a more efficient ECP using only one pair of less-entangled atoms, an auxiliary atom, and a photon, with repeated use for higher success rates.

Findings

Higher success probability with fewer resources.

Protocol remains effective under practical imperfections.

Potential applications in quantum information processing.

Abstract

A recent paper (Phys. Rev. A 86, 034305 (2012)) proposed an entanglement concentration protocol (ECP) for less-entangled $N$-atom GHZ state with the help of the photonic Faraday rotation. It is shown that the maximally entangled atom state can be distilled from two pairs of less-entangled atom states. In this paper, we put forward an improved ECP for arbitrary less-entangled N-atom GHZ state with only one pair of less-entangled atom state, one auxiliary atom and one auxiliary photon. Moreover, our ECP can be used repeatedly to obtain a higher success probability. If consider the practical operation and imperfect detection, our protocol is more efficient. This ECP may be useful in current quantum information processing.