Generation of highly retrievable atom photon entanglement with a millisecond lifetime via a spatially multiplexed cavity

Abstract

Qubit memory that is entangled with photonic qubit is the building block for long distance quantum repeaters. Cavity enhanced and long lived spin wave photon entanglement has been demonstrated by applying dual laser beams onto optical-lattice atoms. However, owing to cross readouts by two beams, retrieval efficiency of spin wave qubit is decreased by one quarter compared to that of single mode spin wave at all storage times. Here, by coupling cold atoms to two modes of a polarization interferometer based cavity, we achieve perfect qubit retrieval in cavity enhanced and long lived atom photon entanglement. A write laser beam is applied onto cold atoms, we then create a magnetic field insensitive spin wave qubit that is entangled with the photonic qubit encoded onto two arms of the interferometer. The spin wave qubit is retrieved by a read beam, which avoids the cross readouts. Our experiment demonstrates 540μs storage time at 50% intrinsic qubit retrieval efficiency, which is 13.5 times longer than the best reported result.

References in corpus (19)

• The Quantum Internet
• Quantum Repeaters with Photon Pair Sources and Multi-Mode Memories
• Mapping photonic entanglement into and out of a quantum memory
• Quantum Storage of Photonic Entanglement in a Crystal
• Towards a global quantum network
• A millisecond quantum memory for scalable quantum networks
• Efficient quantum memory for single photon polarization qubits
• Quantum storage of entangled telecom-wavelength photons in an erbium-doped optical fibre
• Efficient and long-lived quantum memory with cold atoms inside a ring cavity
• Coherent Optical Memory with High Storage Efficiency and Large Fractional Delay
• Experimental realization of a multiplexed quantum memory with 225 individually accessible memory cells
• Interfacing Collective Atomic Excitations and Single Photons
• 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
• Efficient retrieval of a single excitation stored in an atomic ensemble
• Decoherence-protected memory for a single-photon qubit
• Optimal Storage and Retrieval of Single-Photon Waveforms
• Cavity-Enhanced Atom-Photon Entanglement with Subsecond Lifetime