Error-detected state transfer and entanglement in a superconducting quantum network: Part 2*

We use a quantum bus to transfer qubits and generate entanglement across a two-node network. Crucially, both of these operations can be made less sensitive to loss in the bus by encoding information with multiple photons and detecting loss errors. We transfer a bosonic qubit, tracking loss events to preserve the quantum information, achieving an error rate as low as that in a single-photon encoding. Further, we generate entanglement with two-photon interference and postselect against errors with local parity measurements, producing a Bell state with a high success probability and half the error of single photon case. These results provide several approaches for high-fidelity gates in a quantum network.