Sharing information over computer networks for private, business or science-related communication is part of our everyday lives. In the future, we may use protocols based on quantum physics to realize secure communication or to perform distributed quantum information processing exceeding the capabilities of classical computers and communication networks. In our work, we take a key step toward a future quantum network by realizing a fully deterministic quantum communication protocol between two remote superconducting quantum circuits. We accomplish this protocol by emitting a single, time-symmetric, itinerant microwave photon from one node of the network and absorb at another one to transmit a quantum bit of information and establish entanglement between two distant quantum nodes on-demand.
Nature 558, 264-267 (2018)