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Single-photon two-qubit SWAP gate for entanglement manipulation

Marco Fiorentino·Taehyun Kim·Franco N. C. Wong
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Abstract

A SWAP operation between different types of qubits of single photons is essential for manipulating hyperentangled photons for a variety of applications. We have implemented an efficient SWAP gate for the momentum and polarization degrees of freedom of single photons. The SWAP gate was utilized in a single-photon two-qubit quantum logic circuit to deterministically transfer momentum entanglement between a pair of down-converted photons to polarization entanglement. The polarization entanglement thus obtained violates Bell's inequality by more than 150 standard deviations.

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Marco Fiorentino, Taehyun Kim, Franco N. C. Wong. 2004-07-16. Single-photon two-qubit SWAP gate for entanglement manipulation. https://doi.org/10.1103/physreva.72.012318

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