Linear optical generation of multipartite entanglement with conventional photon detectors
Hong‐Fu Wang, Shou Zhang · Physical Review A · 2009
A simple experimental scheme is proposed to generate a three-photon entangled $W$ state and a genuine four-photon entangled state $|{\ensuremath{\chi}}^{00}⟩$ that has many interesting entanglement properties and possible applications in quantum information processing. These multipartite entangled states can be generated with a certain success probability. We show that even when the quantum efficiency of the detector is $\ensuremath{\eta}=0.75$, the success probability can reach $2.8\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}$ for $W$-state production and $3.0\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}9}$ for $|{\ensuremath{\chi}}^{00}⟩$-state production. The scheme is based only on simple linear optical elements and conventional photon detectors, which greatly decrease the experimental difficulty of implementing linear optical quantum computation.