Recent studies have shown long-distance entanglement using NV centers, atoms, and quantum dots with single-photon time-bin encoding. We propose a method to entangle remote superconducting qubits via microwave-optical transduction using multi-time-bin states. By adapting conventional entanglement swapping techniques, fidelity improves from 0. 75 to 0. 98 in transduction systems, and 0. 66 to 0. 89 in noisy channels. The protocol mitigates thermal noise without relying on purification and offers a practical path toward scalable, heterogeneous quantum systems.
Wu et al. (2025) studied this question.