arXiv:2012.15459 · PRX Quantum
Random-Receiver Quantum Communication
Some Sankar Bhattacharya, Ananda G. Maity, Tamal Guha, Giulio Chiribella, Manik Banik
Abstract
We introduce the task of random-receiver quantum communication, in which a sender transmits a quantum message to a receiver selected from a list of n spatially separated parties.At the moment of transmission, the choice of receiver is unknown to the sender.Later, it becomes known to the n parties, who coordinate their actions by exchanging classical messages.In normal conditions, random-receiver quantum communication requires a noiseless quantum communication channel between the sender and each of the n receivers.In contrast, we show that random-receiver quantum communication can take place through noisy, entanglement-breaking channels if the order of such channels is coherently controlled by a quantum bit that is accessible through measurements.While this phenomenon is achieved with a single control qubit, it cannot be mimicked by adding a noiseless qubit channel from the sender to any of the receivers, or more generally, from the sender to any subset of k < n parties.