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arXiv · 1905.08184

Entanglement and non-locality between disparate solid-state quantum memories mediated by photons

Marcel. li Grimau Puigibert·Mohsen Falamarzi Askarani·Jacob H. Davidson·Varun B. Verma·Matthew D. Shaw·Sae Woo Nam·Thomas Lutz·Gustavo C. Amaral·Daniel Oblak·Wolfgang Tittel
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Abstract

Entangling quantum systems with different characteristics through the exchange of photons is a prerequisite for building future quantum networks. Proving the presence of entanglement between quantum memories for light working at different wavelengths furthers this goal. Here, we report on a series of experiments with a thulium-doped crystal, serving as a quantum memory for 794 nm photons, an erbium-doped fibre, serving as a quantum memory for telecommunication-wavelength photons at 1535 nm, and a source of photon pairs created via spontaneous parametric down-conversion. Characterizing the photons after re-emission from the two memories, we find non-classical correlations with a cross-correlation coefficient of $g^{(2)}_{12} = 53\pm8$; entanglement preserving storage with input-output fidelity of $\mathcal{F}_{IO}\approx93\pm2\%$; and non-locality featuring a violation of the Clauser-Horne-Shimony-Holt Bell-inequality with $S= 2.6\pm0.2$. Our proof-of-principle experiment shows that entanglement persists while propagating through different solid-state quantum memories operating at different wavelengths.

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Marcel. li Grimau Puigibert, Mohsen Falamarzi Askarani, Jacob H. Davidson, Varun B. Verma, Matthew D. Shaw, Sae Woo Nam, Thomas Lutz, Gustavo C. Amaral, Daniel Oblak, Wolfgang Tittel. 2019-05-20. Entanglement and non-locality between disparate solid-state quantum memories mediated by photons. https://doi.org/10.1103/physrevresearch.2.013039

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