Realizing quantum speedup for practically relevant, computationally hard problems is a central challenge in quantum information science. Using Rydberg atom arrays with up to 289 qubits in two spatial dimensions, we experimentally investigate quantum algorithms for solving the Maximum Independent Set problem. We use a hardware-efficient encoding associated with Rydberg blockade, realize closed-loop optimization to test several variational algorithms, and subsequently apply them to systematically explore a class of graphs with programmable connectivity. We find the problem hardness is controlled by the solution degeneracy and number of local minima, and experimentally benchmark the quantum algorithm's performance against classical simulated annealing. On the hardest graphs, we observe a superlinear quantum speedup in finding exact solutions in the deep circuit regime and analyze its origins.
@article{arxiv.2202.09372,
title = {Quantum Optimization of Maximum Independent Set using Rydberg Atom Arrays},
author = {Sepehr Ebadi and Alexander Keesling and Madelyn Cain and Tout T. Wang and Harry Levine and Dolev Bluvstein and Giulia Semeghini and Ahmed Omran and Jinguo Liu and Rhine Samajdar and Xiu-Zhe Luo and Beatrice Nash and Xun Gao and Boaz Barak and Edward Farhi and Subir Sachdev and Nathan Gemelke and Leo Zhou and Soonwon Choi and Hannes Pichler and Shengtao Wang and Markus Greiner and Vladan Vuletic and Mikhail D. Lukin},
journal= {arXiv preprint arXiv:2202.09372},
year = {2022}
}
Comments
10 pages, 5 figures, Supplementary materials at the end