Robust quantum repeater with atomic ensembles and single-photon sources
Fang-Yu Hong, Shi‐Jie Xiong · Physical Review A · 2009
We present an efficient scheme for generating high-fidelity entanglement locally which is essential for quantum repeater protocols. Two local ``polarization'' entangled states of atomic ensembles $u$ and $d$ are generated by absorbing a single photon emitted by on-demand single-photon sources, based on which high-fidelity local entanglement between four ensembles can be established efficiently through Bell-state measurement. Entanglement in basic links and entanglement connection between links are carried out by the use of two-photon interference. In addition to being robust against phase fluctuations in the quantum channels, this scheme may speed up quantum communication with higher fidelity compared with the partial read protocol [Sangouard et al., Phys. Rev. A 77, 062301 (2008)] which may generate entanglement most quickly among the previous schemes with the same ingredients.