Efficient entanglement concentration for arbitrary single-photon multimode W state
Lan Zhou, Yu‐Bo Sheng, W. W. Cheng, Longyan Gong, Shengmei Zhao · Journal of the Optical Society of America B · 2012
We put forward an efficient entanglement concentration protocol (ECP) for recovering the single-photon less-entangled W state into the maximally entangled W state with only two conventional auxiliary photons. The ECP includes two local steps, both of which are based on the weak cross-Kerr nonlinearities and the variable beam splitter (VBS). Benefiting from the cross-Kerr nonlinearities and the VBS, the ECP can be used repeatedly to further concentrate the less-entangled W state. All the advantages indicate that our protocol may be feasible and convenient in current quantum communications areas.