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arXiv · 1408.5310

A nonlocal polarization interferometer for entanglement detection

Brian P. Williams·Travis S. Humble·Warren P. Grice
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Abstract

We report a nonlocal interferometer capable of detecting entanglement and identifying Bell states statistically. This is possible due to the interferometer's unique correlation dependence on the anti-diagonal elements of the density matrix, which have distinct bounds for separable states and unique values for the four Bell states. The interferometer consists of two spatially separated balanced Mach-Zehnder or Sagnac interferometers that share a polarization entangled source. Correlations between these interferometers exhibit non-local interference, while single photon interference is suppressed. This interferometer also allows for a unique version of the CHSH-Bell test where the local reality is the photon polarization. We present the relevant theory and experimental results.

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Brian P. Williams, Travis S. Humble, Warren P. Grice. 2014-10-22. A nonlocal polarization interferometer for entanglement detection. https://doi.org/10.1103/physreva.90.042121

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