Graph-Aware Exact Branch-and-Bound with Device Profiles for Static Qubit Allocation

Abstract:Static qubit allocation maps a circuit's logical qubits to a sparse physical device while minimising an interaction-weighted physical-distance cost function, yielding a rectangular quadratic assignment problem. Existing work combines strong lower bounds with distributed branch-and-bound. We integrate graph-aware exact reductions with an engineering bundle for a lightweight assignment-bound path: unavoidable assigned-cost filtering, incrementally maintained root-orbit and prefix-stabilizer symmetry pruning, conditioned parent-LAP screening, and circuit-independent physical device profiles. On 21 relatively easy Melbourne instances and six Boeblingen instances completed by the GLB baseline, the final single-thread configuration provides geometric-mean speedups of 2.98x and 13.27x, respectively. With 60 threads on one shared-memory server, all instances in the final Boeblingen--Cairo experiment are certified optimal within half an hour, excluding one-time device-artifact construction. These results show that graph-aware node processing and engineering the search process substantially reduce the resources required for exact allocation.

arXiv:2608.04058 [quant-ph]

(or arXiv:2608.04058v1 [quant-ph] for this version)

https://doi.org/10.48550/arXiv.2608.04058 Focus to learn more arXiv-issued DOI via DataCite

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