Many facets of multiparty broadcasting of known quantum information using optimal quantum resource

TL;DR

This paper clarifies the distinction between quantum broadcasting and remote state preparation for known quantum states, demonstrating optimal broadcasting methods, analyzing noise effects, and providing a proof-of-concept implementation on IBM quantum hardware.

Contribution

It establishes the relation between remote state preparation and quantum broadcasting, introduces optimal schemes for broadcasting known states, and reports a practical IBM quantum implementation.

Findings

Optimal deterministic and probabilistic broadcasting schemes for known quantum states.

Analysis of noise effects on broadcasting schemes.

Successful proof-of-concept implementation on IBM quantum computer.

Abstract

The no-quantum broadcasting theorem which is a weaker version of the nocloning theorem restricts us from broadcasting completely unknown quantum information to multiple users. However, if the sender is aware of the quantum information (state) to be broadcasted then the above restriction disappears and the task reduces to a multiparty remote state preparation. Without recognizing this fact, several schemes for broadcasting of known quantum states have been proposed in the recent past (e.g., Quantum Inf Process (2017) 16:41) and erroneously/misleadingly referred to as protocols for quantum broadcasting. Here we elaborate on the relation between the protocols of remote state preparation and those of broadcasting of known quantum information and show that it's possible to broadcast known quantum information to multiple receivers in deterministic as well as probabilistic manner with optimal resources. Further, the effect of noise on such schemes, and some new facets (like joint broadcasting) of such schemes have been discussed. A proof of principle realization of the proposed optimal scheme using IBM quantum computer is also reported. Possibilities of generalizations of the so-called broadcasting schemes and potential applications are also discussed with appropriate importance.