Optimizing, Controlling, and Mitigating Quantum Defects

As the scale of superconducting quantum computers grows, modular architectures are playing an increasingly important role. In this talk, I will discuss modular architectures in the context of existing and planned IBM quantum computers. Modularity can be hierarchical and take several forms, including real-time classical communication, short- and long-range microwave links between quantum processors, and room-temperature optical connections relying on quantum transducers. Although quantum transduction is not currently at the technical readiness level to be on IBM’s quantum roadmap, I will present a model mapping the properties of transducers to two-qubit gate fidelities, which clarifies how close to viability it is. Moreover, I will present entanglement distillation protocols designed to mitigate errors deriving from transducers, which were inspired by recent demonstrations of remote entanglement in defect qubits. Together with the continually increasing connectivity and decreasing error rates of superconducting qubits, modularity is slated to be a key component of forthcoming quantum computers.