近日，美国加州理工学院的Manuel Endres&Adam L. Shaw及其研究小组与美国麻省理工学院的Soonwon Choi等人合作并取得一项新进展。经过不懈努力，他们在60原子模拟量子模拟器上对高度纠缠态进行基准测试。相关研究成果已于2024年3月20日在国际权威学术期刊《自然》上发表。
该研究团队采用60原子模拟的里德伯量子模拟器，进行保真基准测试和混合态纠缠估计，成功达到高纠缠熵状态。在这种状态下，精确的经典模拟变得不切实际。该研究设计的基准测试协议，通过与近似经典算法的比较进行推断，且具备不同的纠缠限制。接着，研究人员开发并展示了实验混合态纠缠的估计器，该实验在性能上与执行随机电路演化的最先进数字量子器件相当。
最后，他们对比了实验保真度与各种近似经典算法的保真度，发现仅有他们引入的算法能够与实验在所用经典硬件上保持同步。这项研究为评估模拟和数字量子器件在超经典精确状态下产生纠缠的能力提供了新的模型，同时也凸显了量子系统与经典系统之间日益扩大的鸿沟。
据悉，量子系统已进入竞争状态，其中经典计算机需依赖近似手段来表征高度纠缠的量子态。然而，在这种超越经典的精确状态下，量子与经典系统间的保真度比较仅限于数字量子器件，且实验中实际纠缠内容的估算问题仍待解决。
附：英文原文
Title: Benchmarking highly entangled states on a 60-atom analogue quantum simulator
Author: Shaw, Adam L., Chen, Zhuo, Choi, Joonhee, Mark, Daniel K., Scholl, Pascal, Finkelstein, Ran, Elben, Andreas, Choi, Soonwon, Endres, Manuel
Issue&Volume: 2024-03-20
Abstract: Quantum systems have entered a competitive regime in which classical computers must make approximations to represent highly entangled quantum states. However, in this beyond-classically-exact regime, fidelity comparisons between quantum and classical systems have so far been limited to digital quantum devices, and it remains unsolved how to estimate the actual entanglement content of experiments. Here, we perform fidelity benchmarking and mixed-state entanglement estimation with a 60-atom analogue Rydberg quantum simulator, reaching a high-entanglement entropy regime in which exact classical simulation becomes impractical. Our benchmarking protocol involves extrapolation from comparisons against an approximate classical algorithm, introduced here, with varying entanglement limits. We then develop and demonstrate an estimator of the experimental mixed-state entanglement, finding our experiment is competitive with state-of-the-art digital quantum devices performing random circuit evolution. Finally, we compare the experimental fidelity against that achieved by various approximate classical algorithms, and find that only the algorithm we introduce is able to keep pace with the experiment on the classical hardware we use. Our results enable a new model for evaluating the ability of both analogue and digital quantum devices to generate entanglement in the beyond-classically-exact regime, and highlight the evolving divide between quantum and classical systems.
DOI: 10.1038/s41586-024-07173-x
Source: https://www.nature.com/articles/s41586-024-07173-x
Nature：《自然》，创刊于1869年。隶属于施普林格·自然出版集团，最新IF：69.504
官方网址：http://www.nature.com/
投稿链接：http://www.nature.com/authors/submit_manuscript.html