Fig. 2: The entanglement distillation proposal and its enhancement on entanglement fidelity and rate.
From: Towards entanglement distillation between atomic ensembles using high-fidelity spin operations
a The energy-level diagram and the entanglement distillation proposal. A and B represent two distant communication nodes. The subscript e and n denotes the electron and nuclear degrees of freedom, respectively. Anti-Stokes, AS; beam splitter, BS; Detector, D. b The fidelity after entanglement distillation as a function of the iteration times with the initial fidelity of 0.2 (triangle symbol and yellow line), 0.6 (dot symbol and green line) and 0.8 (square symbol and purple line), respectively. c The speedup coefficient Rs as a function of the nesting levels by increasing the excitation rate pc and utilizing entanglement distillation after the last level’s entanglement connection process. pc = 10−3 (triangle symbol and yellow line), 10−4 (dot symbol and green line), 10−5 (square symbol and purple line). The dot, dash, solid line represents the total efficiency η = 90%, 95%, 100%, respectively.
