A quantum control system for long-lived logical qubits

Three intertwined challenges are facing the field of superconducting quantum computing on its advance towards fault-tolerance: realizing practical quantum error correction, raising standards of qubit fidelity, and demonstrating scalability of the technology as a whole. When mastered, the next milestone of building long-lived logical qubits is within reach.

The quantum control system connecting end users with quantum processing units is central to all of these challenges. Key requirements on the control system include full-stack scalability, high signal fidelity and timing precision, and low-latency communication and processing capabilities. Here we present a control system engineered for the challenge of building long-lived logical qubits. Its key features are an analog front end optimized for “five nines” gate fidelities on physical qubits, a system architecture designed for best match with logical qubit implementations, and high-bandwidth interfaces to integrate the system's processing capabilities tightly with classical compute resources.