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arXiv · 1904.02537

Time Entanglement between a Photon and a Spin Wave in a Multimode Solid-state Quantum Memory

Kutlu Kutluer·Emanuele Distante·Bernardo Casabone·Stefano Duranti·Margherita Mazzera·Hugues de Riedmatten
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Abstract

The generation and distribution of entanglement are key resources in quantum repeater schemes. Temporally multiplexed systems offer time-bin encoding of quantum information which provides robustness against decoherence in fibers, crucial in long distance communication. Here we demonstrate the direct generation of entanglement in time between a photon and a collective spin excitation in a rare earth ion doped ensemble. We analyze the entanglement by mapping the atomic excitation onto a photonic qubit and by using time-bin qubits analyzers implemented with another doped crystal using the atomic frequency comb technique. Our results provide a solid-state source of entangled photons with embedded quantum memory. Moreover, the quality of the entanglement is high enough to enable a violation of a Bell inequality by more than two standard deviations.

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Kutlu Kutluer, Emanuele Distante, Bernardo Casabone, Stefano Duranti, Margherita Mazzera, Hugues de Riedmatten. 2019-04-04. Time Entanglement between a Photon and a Spin Wave in a Multimode Solid-state Quantum Memory. https://doi.org/10.1103/physrevlett.123.030501

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