High teleportation rates using cold-atom ensemble based quantum repeaters with Rydberg blockade

Abstract

We present a simplified version of a repeater protocol in a cold neutral-atom ensemble with Rydberg excitations optimized for two-node entanglement generation and describe a protocol for quantum teleportation. Our proposal draws from previous proposals [Zhao, {\sl et al.}, Phys. Rev. A {\bf 81}, 052329 (2010)] and [Han, {\sl et al.} Phys. Rev. A {\bf 81}, 052311 (2010)] who described efficient and robust protocols for long-distance entanglement with many nodes. Using realistic experimental values we predict an entanglement generation rate of $\sim$25 Hz and teleportation rate of $\sim$ 5 Hz. Our predicted rates match the current state of the art experiments for entanglement generation and teleportation between quantum memories. With improved efficiencies we predict entanglement generation and teleportation rates of $\sim$7.8 kHz and $\sim$3.6 kHz respectively, representing a two order of magnitude improvement over the currently realized values. Cold-atom ensembles with Rydberg excitations are promising candidates for repeater nodes because collective effects in the ensemble can be used to deterministically generate a long-lived ground state memory which may be efficiently mapped onto a directionally emitted single photon.