Distributing Compilation to Enable High Throughput Scalable Quantum Workloads

The increasing quality and availability of Quantum Processing Units (QPUs) is fueling a growing interest in quan-tum computing across many technological areas. The resulting increase in demand for QPU resources necessitates Quantum Computing as a Service (QCaaS) providers to support a high throughput of quantum workloads. A major runtime bottleneck in current QCaaS software stacks is the computationally-intensive compilation step which requires significant compute. To address this, Oxford Quantum Circuits has introduced distributed compilation whereby quantum programs are com-piled in parallel and stored until the QPU is available. This has replaced our previous serial compilation approach where each program was compiled immediately prior to execution. From experiments using our production compilers and a simulated backend representing the QPU, we show that distributed com-pilation has resulted in a 78 % reduction in processing time as compared to serial compilation. This demonstrates that there are sizeable performance gains to program throughput attainable through the introduction of distributed compilation into a QCaaS architecture. We posit that the usefulness of this feature will only grow given the increasing complexity of quantum programs and the growing popularity of quantum-classical hybrid algorithms.