A neutral-atom Hubbard quantum simulator in the cryogenic regime

• 成果类型: Article
• 署名作者: Xu, Muqing; Kendrick, Lev Haldar; Kale, Anant; Gang, Youqi; Feng, Chunhan; Zhang, Shiwei; Young, Aaron W.; Lebrat, Martin; Greiner, Markus
• 署名单位: Harvard University; Simons Foundation; Flatiron Institute
• 刊物名称: Nature
• ISSN/ISSBN: 0028-2627
• DOI: 10.1038/s41586-025-09112-w
• 发表日期: 2025-06-26
• 关键词: ultracold fermions; MODEL; physics

摘要

Ultracold fermionic atoms in optical lattices offer pristine realizations of Hubbard models1, which are fundamental to modern condensed-matter physics2,3. Despite notable advancements4, 5-6, the accessible temperatures in these optical lattice material analogues are still too high to address many open problems7, 8, 9-10. Here we demonstrate a several-fold reduction in temperature6,11, 12-13, bringing large-scale quantum simulations of the Hubbard model into an entirely new regime. This is accomplished by transforming a low-entropy product state into strongly correlated states of interest via dynamic control of the model parameters14,15, which is extremely challenging to simulate classically10. At half-filling, the long-range antiferromagnetic order is close to saturation, leading to a temperature of T/t=0.05-0.05+0.06\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$T/t=0.0{5}_{-0.05}<^>{+0.06}$$\end{document} based on comparisons with numerically exact simulations. Doped away from half-filling, it is exceedingly challenging to realize systematically accurate and predictive numerical simulations9. Importantly, we are able to use quantum simulation to identify a new pathway for achieving similarly low temperatures with doping. This is confirmed by comparing short-range spin correlations to state-of-the-art, but approximate, constrained-path auxiliary-field quantum Monte Carlo simulations16, 17-18. Compared with the cuprates2,19,20, the reported temperatures correspond to a reduction from far above to below room temperature, at which physics such as the pseudogap and stripe phases may be expected3,19,21, 22, 23-24. Our work opens the door to quantum simulations that solve open questions in material science, develop synergies with numerical methods and theoretical studies, and lead to discoveries of new physics8,10.