English

NISQ-compatible approximate quantum algorithm for unconstrained and constrained discrete optimization

Quantum Physics 2023-11-22 v3 Optimization and Control

Abstract

Quantum algorithms are getting extremely popular due to their potential to significantly outperform classical algorithms. Yet, applying quantum algorithms to optimization problems meets challenges related to the efficiency of quantum algorithms training, the shape of their cost landscape, the accuracy of their output, and their ability to scale to large-size problems. Here, we present an approximate gradient-based quantum algorithm for hardware-efficient circuits with amplitude encoding. We show how simple linear constraints can be directly incorporated into the circuit without additional modification of the objective function with penalty terms. We employ numerical simulations to test it on MaxCut problems with complete weighted graphs with thousands of nodes and run the algorithm on a superconducting quantum processor. We find that for unconstrained MaxCut problems with more than 1000 nodes, the hybrid approach combining our algorithm with a classical solver called CPLEX can find a better solution than CPLEX alone. This demonstrates that hybrid optimization is one of the leading use cases for modern quantum devices.

Keywords

Cite

@article{arxiv.2305.14197,
  title  = {NISQ-compatible approximate quantum algorithm for unconstrained and constrained discrete optimization},
  author = {M. R. Perelshtein and A. I. Pakhomchik and Ar. A. Melnikov and M. Podobrii and A. Termanova and I. Kreidich and B. Nuriev and S. Iudin and C. W. Mansell and V. M. Vinokur},
  journal= {arXiv preprint arXiv:2305.14197},
  year   = {2023}
}

Comments

Accepted for publication in Quantum

R2 v1 2026-06-28T10:43:12.482Z