Quantum mechanics

Quantum computer

Engineering

Telecommunications

Computer science

Physics

Quantum entanglement

Optics

Transmon

Quantum information science

Coaxial cable

Superconductivity

Electronic engineering

Resonator

Quantum

Qubit

Topology (electrical circuits)

Cable gland

Superconducting quantum computing

Electrical engineering

npj Quantum Information

We propose and experimentally demonstrate an efficient scheme for bidirectional and deterministic photonic communication between two remote superconducting modules. The two chips, each consists of a transmon, are connected through a one-meter long coaxial cable that is coupled to a dedicated “communication” resonator on each chip. The two communication resonators hybridize with a mode of the cable to form a dark “communication mode” that is highly immune to decay in the coaxial cable. We overcome the various restrictions of quantum communication channels established by other recent approaches in deterministic communication for superconducting qubits. Our approach enables bidirectional communication, and eliminates the high insertion loss and large volume footprint of circulators. We modulate the transmon frequency via a parametric drive to generate sideband interactions between the transmon and the communication mode. We demonstrate bidirectional single-photon transfer with a success probability exceeding 60%, and generate an entangled Bell pair with a fidelity of 79.3 ± 0.3%.

Deterministic bidirectional communication and remote entanglement generation between superconducting qubits