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 show… (More)
We report experimental demonstration of an optical gate that increases the size of polarization-entangled W-states by accessing only one qubit, and discuss strategies of local expansion and fusion to prepare large scale W-state networks.
We have theoretically proposed and experimentally demonstrated that two EPR photon pairs can be transformed into a three-photon W state by local operation and classical communication (LOCC). The fidelity of the final state to the ideal W state was 0.778 ± 0.043. The obtained expectation value of the witness operator for distinguishing between the… (More)