Theoretical and experimental study on local expansion and transformation of photonic W states

Ozdemir, Tashima, Yamamoto Yamamoto +2 more

Şahin Kaya Özdemir, Toshiyuki Tashima, Takashi Yamamoto +2 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.

Matthieu Bellec, Georgios M. Nikolopoulos, Stelios Tzortzakis

Toshiyuki Tashima, T. Wakatsuki, Şahin Kaya Özdemir +3 more

We propose and experimentally demonstrate a transformation of two Einstein-Podolsky-Rosen photon pairs distributed among three parties into a three-photon W state using local operations and classical communication. We then characterize the final state using quantum state tomography on the three-photon state and on its marginal bipartite states. The fidelity of the final state to the ideal W state is 0.778+/-0.043 and the expectation value for its witness operator is -0.111+/-0.043 implying the success of the proposed local transformation.

Toshiyuki Tashima, Şahin Kaya Özdemir, Takashi Yamamoto +2 more

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.

T. Hönigl-Decrinis, A. Yu. Dmitriev, Rais S. Shaikhaidarov +2 more