Long-distance quantum communication Quantum repeater Entanglement: a) Generation b) Distribution c)Purification d) Swapping e)Storage Briegel et al., Phys. Rev. Lett.81, 5932(1998)Long-distance quantum communication: Quantum repeater Briegel et al., Phys. Rev. Lett. 81, 5932 (1998) Entanglement: a) Generation b) Distribution c) Purification d) Swapping e) Storage