Entanglement distillation

Summary

Entanglement distillation is the conversion of many copies of a weakly or noisily entangled state into fewer copies of nearly perfect Bell states. The parties may use only LOCC, local operations and classical communication. The best asymptotic rate of this conversion is the distillable entanglement of the state. Distillation is needed because protocols such as teleportation require pure maximally entangled pairs, while real sources produce noisy ones.