2025
Published
Local optimization
Local Optimization of Quantum Circuits
Optimize circuits.
One part at a time.
The example is described below.
The sequence X, H | H, X does nothing overall, yet neither half can be simplified on its own. A window across the seam finds the cancellation: H H first, then X X.
This small identity circuit explains a local rewrite. It is not a claim that every circuit reaches a global optimum.
Work locally. Keep a guarantee.
Cut circuits into smaller parts, optimize each part, and join the results with local optimality guarantees.
IEEE QCE2025 / QSYSBest Paper Award, first place in QSYS track
How the method works.
Finding the best version of a large quantum circuit can be expensive. Smaller parts are easier to optimize. But a cut can hide a useful simplification between two neighbouring parts.
The method cuts the circuit, optimizes each part, then checks across the joins when needed. Its guarantees apply to the chosen optimization routine, cost rule and allowed subcircuit size. They do not imply the best circuit among all possible circuits.
For a small example, allow only X and H gates and read this sequence from left to right: X → H | H → X. The line marks a cut. Neither half can lose a gate on its own. Across the cut, the two H gates cancel. The two X gates then cancel too. Four gates become none.
This is a teaching example of why the joins matter, not a reported benchmark. See the conference paper page and extended paper for the algorithm, local optimality conditions and evaluation.
Sources &
citation.
2025 IEEE International Conference on Quantum Computing and Engineering (QCE)
2025 · Published
IEEE QCE2025
View the citation
@inproceedings{local-optimization-2025,
title = {{Local Optimization of Quantum Circuits}},
author = {Jatin Arora and Mingkuan Xu and Sam Westrick and Pengyu Liu and Dantong Li and Yongshan Ding and Umut A. Acar},
year = {2025},
booktitle = {2025 IEEE International Conference on Quantum Computing and Engineering (QCE)},
url = {https://mingkuan.taichi.graphics/publication/2025-oac/},
note = {Extended version: arXiv:2502.19526. Best Paper Award, first place in QSYS track.}
}