Experimental demonstration of entangling gates across chips in a multi-core QPU

In addition to communication networks, routers and repeaters, actively under development in the context of quantum information processing, multi-core architectures are a critical component of distributed computing. As quantum processors scale and quantum networks are realized, motherboards will be required to coherently route information between chips, enabling entanglement between cores in a quantum processor or possibly between quantum memory or processing modules deriving from different physical architectures. Furthermore, for superconducting qubit integrated circuits, a modular processor composed of several smaller individual chips mitigates the impact of exponentially decreasing chip yield as the number of qubits per die increases. Towards these aims, we present here experimental results from a multi-core quantum processing unit: a 32-qubit platform formed from short-range interconnects across four 8-qubit chips. We show that this inter-chip coupling does not significantly impact single-qubit or two-qubit performance, and conclude with examples of high fidelity multi-qubit algorithms across these inter-chip edges.