General bounds for sender-receiver capacities in multipoint quantum communications

Understand

We investigate the maximum rates for transmitting quantum information, distilling entanglement, and distributing secret keys between a sender and a receiver in a multipoint communication scenario, with the assistance of unlimited two-way classical communication involving all parties.

• First we consider the case where a sender communicates with an arbitrary number of receivers, so called quantum broadcast channel.
• Here we also provide a simple analysis in the bosonic setting where we consider quantum broadcasting through a sequence of beamsplitters.
• Then, we consider the opposite case where an arbitrary number of senders communicate with a single receiver, so called quantum multiple-access channel.