Fig. 1: Processes of the Duan–Lukin–Cirac–Zoller scheme.
From: Towards entanglement distillation between atomic ensembles using high-fidelity spin operations
a Write process. An off-resonant laser pulse with detuning of δ to \(\left|g\right\rangle \to \left|e\right\rangle\) transition induces a Stokes (S) photon with a small probability. b Read process. A resonant laser pulse drives single excitation from \(\left|s\right\rangle\) to \(\left|e\right\rangle\), inducing an anti-Stokes (AS) photon correlated with the Stoke photon. c Entanglement generation process. The stokes photons revealed by ensemble A and B interfere on a beam splitter (BS). d The first level entanglement connection. e Extending the communication length by utilizing entanglement connection. The single-photon detector D1 and D2 are used to detect the Stokes photon in the entanglement generation process, while D3 and D4 are utilized to detect the anti-Stokes photon in the entanglement connection process. L0 denotes the distance between two neighboring nodes.
