Liquid Metal Enabled Modular Architecture of Superconducting Quantum Processor

A fault-tolerant quantum computer requires a large number of qubits. Modular architecture is one of the means to realize scalability of qubits, where individual modules with several qubits may be screened, selected, replaced, and then integrated into the large quantum system. While various modular architectures have been proposed, they are either permanent or space-inefficient, making the replacement of modules or compact configurations challenging and ultimately limiting the scalability of the system. Here we report high internal quality factor coplanar waveguide resonators (CPWR) interconnected by gallium alloy droplets. We discuss the loss mechanism induced by this liquid metal by comparing the results to solid-state CPWR with similar geometries. Having shown the potential of the basic building blocks, we envision a space-saving, 3D large-scale superconducting quantum processor enabled by liquid metals.