Controlled Cyclic and Bidirectional Hybrid Quantum Communication of Arbitrary Two‐Qubit States

Abstract Hybrid quantum communication with the combination of quantum teleportation and remote preparation is hopeful for promoting the development of quantum networks and enriching the diversity of quantum network communication. To improve the communication efficiency and enhance the scalability of the quantum networks, a meaningful protocol for controlled cyclic and bidirectional hybrid quantum communication of arbitrary two‐qubit states is proposed, which allows quantum information to be transmitted simultaneously in both directions among multiple participants. With the permission of one controller, each observer can simultaneously transmit arbitrary known two‐qubit states and unknown ones to their adjacent observers, by implementing remote preparation and quantum teleportation in the clockwise and counterclockwise directions. Furthermore, the participants just carry out some quantum measurements and recovery operations to achieve the communication target, and the desired states can be attained with a unit success probability, thus the protocol is deterministic. Finally, some comparisons are also made with other similar protocols, which shows that the protocol is better in qubit efficiency and communication capacity.