Quantum broadcast channels with cooperating decoders: An information-theoretic perspective on quantum repeaters

Communication over a quantum broadcast channel with cooperation between the receivers is considered. The first form of addressed classical conferencing, where receiver 1 can send messages to 2. Another setting involves teleport state When not required recover information and its sole purpose help transmission 2, model reduces primitive relay channel. conferencing intimately related repeaters as sender, 1, 2 be viewed transmitter, repeater, destination receiver, respectively. We develop lower upper bounds on capacity region in each setting. In particular, cutset bound decode-forward are derived for Furthermore, we present an entanglement-formation bound, virtual simulated through conference link. At last, show that opposed multiple access entangled encoders, entanglement decoders does increase communication rates dual.