Local expansion of photonic W state using a polarization-dependent beamsplitter
Toshiyuki Tashima, Şahin Kaya Özdemir, Takashi Yamamoto, Masato Koashi, Nobuyuki Imoto · New Journal of Physics · 2009
We propose a simple probabilistic optical gate to expand polarization entangled W states. The gate uses one polarization-dependent beamsplitter and a horizontally polarized single photon as an ancilla. The gate post-selectively expands N -photon W states to ( N +1)-photon W states. A feasibility analysis considering the realistic experimental conditions shows that the scheme is within the reach of the current quantum optical technologies.