A Chiral Quantum Interconnect for a Modular Superconducting Quantum Processor

Microwave-frequency quantum interconnects are necessary to facilitate entanglement distribution between non-local computational nodes of a superconducting quantum processor. However, many existing architectures are constrained by node connectivity and lack of directionality. In previous works, we demonstrated a chiral quantum interconnect module that leverages quantum interference to emit and absorb microwave photons on demand in a chosen direction, in which two chips in separate microwave packages were connected via a coaxial cable [1, 2, 3]. In this work, we present a simplified module design that achieves the same functionality with fewer qubits and a simplified gate sequence for single-photon emission and absorption. Furthermore, this design is compatible with chiral, driven dissipative entanglement protocols that allow one to simultaneously entangle arbitrary pairs of modules [4, 5]. Additionally, we present preliminary designs of a multi-chip-module system, in which multiple modules are flip-chip bonded to a common interposer, which hosts the waveguide interconnect. This quantum network architecture enables multiple approaches for all-to-all entanglement generation between non-local processors for modular and extensible quantum computation. 

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

 

[3] Almanakly, A., Yankelevich, B. et al. Nat. Phys. 21, 825-830 (2025)

 

[4] Pichler, H., et al. Phys. Rev. A 91, 042116 (2015)

 

[5] Guimond, P.-O., et al., npj Quantum Information 6 (2020)