Remote Entanglement of Superconducting Qubits using Microwave Photon Emission/Absorption Modules and Waveguide QED

In this talk, we present a demonstration of remote entanglement via chiral photon emission and absorption along a waveguide. Superconducting qubits couple to the waveguide at multiple, well-separated locations through modules that deterministically emit and absorb single microwave photons [1]. Using this architecture, we demonstrate directional single-photon emission with 96% fidelity [2] and single-photon absorption exceeding 60% efficiency [3]. We then use partial emission and absorption to generate remote entanglement – a four-qubit W-state – between qubits in the emitter and absorber modules with 62% fidelity [3]. These works along with 3D integration target modular and extensible quantum information processing mediated by quantum interconnects.

[1] Gheeraert, N. et al., Phys. Rev. A 102, 053720 (2020)

[2] Kannan, B., Almanakly, A., et al., Nat. Phys. 19, 394–400 (2023).

[3] Almanakly, A., Yankelevich, B. et al., arXiv:2408.05164 (2024).