High-performance quantum interconnect between bosonic modules beyond transmission loss constraints

Abstract

Distributed quantum computing architectures require high-performance quantum interconnects between quantum information processing units, while previous implementations have been fundamentally limited by transmission line losses. Here, we demonstrate a low-loss interconnect between two superconducting modules using an aluminum coaxial cable, achieving a bus mode quality factor of 1.7e6. By employing SNAIL as couplers, we realize inter-modular state transfer in 0.8 μs via a three-wave mixing process. The state transfer fidelity reaches 98.2% for quantum states encoded in the first two energy levels, achieving a Bell state fidelity of 92.5%. Furthermore, we show the capability to transfer high-dimensional states by successfully transmitting binomially encoded logical states. Systematic characterization reveals that performance constraints have shifted from transmission line losses (contributing merely 0.2% infidelity) to module-channel interface effects and local Kerr nonlinearities. Our work advances the realization of quantum interconnects approaching fundamental capacity limits, paving the way for scalable distributed quantum computing and efficient quantum communications.

References in corpus (9)

• Quantum error correction below the surface code threshold
• On-demand quantum state transfer and entanglement between remote microwave cavity memories
• Deterministic multi-qubit entanglement in a quantum network
• Bosonic quantum error correction codes in superconducting quantum circuits
• Low-loss interconnects for modular superconducting quantum processors
• Error-detected state transfer and entanglement in a superconducting quantum network
• Deterministic quantum teleportation between distant superconducting chips
• A high-efficiency plug-and-play superconducting qubit network
• Dynamic compensation for pump-induced frequency shift in Kerr-cat qubit initialization