Entanglement concentration by ordinary linear optical devices without postselection
Xiang‐Bin Wang, Fan Heng · Physical Review A · 2003
Recently, entanglement concentrations have been experimentaly demonstrated by postselection [T. Yamamoto et al., Nature (London) 421, 343 (2003), and Z. Zhao et al., Phys. Rev. Lett. 90, 207901 (2003)], i.e., to each individual outcome state, one has to destroy it to know whether it has been purified. Here we give proposal for entanglement concentration without any postselection by using only practically existing linear optical devices. In particular, a sophisticated photon detector to distinguish one photon or two photons is not required.