Interfacing single photons from a quantum dot with fiber-confined cold atomic ensemble*

We report our progress on development of a proof-of-principle hybrid quantum repeater. We generate entangled photon pairs from InAsP quantum dots (QD) embedded in semiconductor nanowire and store them in a quantum memory based on an ensemble of laser-cooled caesium atoms confined inside a hollow-core optical fiber. We also investigate the wavelength conversion of single photons generated by the QD (894.6 nm) to telecom wavelength through four-wave mixing in the fiber-confined cloud. Our approach combines the advantages available from a deterministic and tunable solid-state source of bright entangled photon pairs with the potential for long-lived quantum memory and high-efficiency wavelength conversion that are achievable in laser cooled atomic cloud with large optical depths and tight confinement.