PROJECT TITLE :

Bounds on Entanglement Distillation and Secret Key Agreement for Quantum Broadcast Channels

ABSTRACT:

The squashed entanglement of a quantum channel is an additive function of quantum channels, which finds application as an upper sure on the rate at that secret key and entanglement will be generated when using a quantum channel a giant range of times additionally to unlimited classical Communication. This quantity has led to an upper bound of on the capacity of a pure-loss bosonic channel for such a task, where is the average fraction of photons that create it from the input to the output of the channel. The aim of this paper is to extend these results beyond the one-sender single-receiver setting to the more general case of one sender and multiple receivers (a quantum broadcast channel). We employ multipartite generalizations of the squashed entanglement to constrain the rates at which secret key and entanglement can be generated between any subset of the users of such a channel, along the way developing several new properties of those measures. We tend to apply our results to the case of a pure-loss broadcast channel with one sender and 2 receivers.