Modular Compilation for Quantum Chiplet Architectures

As quantum computing technology matures, industry is adopting modular quantum architectures to keep quantum scaling on the projected path and meet performance targets. However, the complexity of chiplet-based quantum devices, coupled with their growing size, presents an imminent scalability challenge for quantum compilation. Contemporary compilation methods are not well-suited to chiplet architectures - in particular, existing qubit allocation methods are often unable to contend with inter-chiplet links, which don't necessarily support a universal basis gate set. Furthermore, existing methods of logical-to-physical qubit placement, swap insertion (routing), unitary synthesis, and/or optimization, are typically not designed for qubit links of significantly varying latency or fidelity. In this work, we propose SEQC, a hierarchical parallelized compilation pipeline optimized for chiplet-based quantum systems, including several novel methods for qubit placement, qubit routing, and circuit optimization. SEQC attains a $9.3\%$ average increase in circuit fidelity (up to $49.99\%$). Additionally, owing to its ability to parallelize compilation, SEQC achieves $3.27\times$ faster compilation on average (up to $6.74\times$) over a chiplet-unaware Qiskit baseline.