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

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.

8 pages and 10 figures

References in corpus (10)

• The Quantum Internet
• Quantum Repeaters with Photon Pair Sources and Multi-Mode Memories
• Quantum Storage of Photonic Entanglement in a Crystal
• A solid state spin-wave quantum memory for time-bin qubits
• Experimental realization of a multiplexed quantum memory with 225 individually accessible memory cells
• A Robust Atom-Photon Entanglement Source for Quantum Repeaters
• Multi-mode and long-lived quantum correlations between photons and spins in a crystal
• Direct measurement of decoherence for entanglement between a photon and stored atomic excitation
• Entanglement of orbital angular momentum states between an ensemble of cold atoms and a photon
• A photon-pair source with controllable delay based on shaped inhomogeneous broadening of rare-earth doped solids