近日，加拿大量子计算公司D-Wave的d H.Amin及其领导的研究小组与美国波士顿大学的Anders W.Sandvik等人合作并取得一项新进展，他们探究了5000量子比特可编程自旋玻璃中的量子临界动力学。相关研究成果已于2023年4月19日在国际权威学术期刊《自然》上发表。

该研究团队成功地在数千个量子比特上实现了量子临界自旋玻璃动力学，利用超导量子退火器快速将自旋玻璃带入低能态。研究人员首先验证了量子退火和薛定谔方程时间演化在小自旋玻璃中的定量一致性。随后，他们在数千个量子比特上测量了三维自旋玻璃的动力学，这是经典多体量子动力学无法模拟的。研究人员提取了关键指数，明确区分了量子退火和类似蒙特卡罗算法的较慢随机动力学，这为大规模量子模拟提供了理论和实验支持，并提供了在能量优化中的规模优势。

据悉，实验结果显示，在无序合金中，通过量子退火的方式比传统的热退火更快地将自旋玻璃带入低能态。自旋玻璃作为一种典型的计算测试平台具有重要的意义，因此在可编程系统中实现这种现象一直是量子优化领域的一个核心挑战。

附：英文原文

Title: Quantum critical dynamics in a 5,000-qubit programmable spin glass

Author: King, Andrew D., Raymond, Jack, Lanting, Trevor, Harris, Richard, Zucca, Alex, Altomare, Fabio, Berkley, Andrew J., Boothby, Kelly, Ejtemaee, Sara, Enderud, Colin, Hoskinson, Emile, Huang, Shuiyuan, Ladizinsky, Eric, MacDonald, Allison J. R., Marsden, Gaelen, Molavi, Reza, Oh, Travis, Poulin-Lamarre, Gabriel, Reis, Mauricio, Rich, Chris, Sato, Yuki, Tsai, Nicholas, Volkmann, Mark, Whittaker, Jed D., Yao, Jason, Sandvik, Anders W., Amin, Mohammad H.

Issue&Volume: 2023-04-19

Abstract: Experiments on disordered alloys^1,2,3 suggest that spin glasses can be brought into low-energy states faster by annealing quantum fluctuations than by conventional thermal annealing. Owing to the importance of spin glasses as a paradigmatic computational testbed, reproducing this phenomenon in a programmable system has remained a central challenge in quantum optimization^{4,5,6,7,8,9,10,11,12,13}. Here we achieve this goal by realizing quantum-critical spin-glass dynamics on thousands of qubits with a superconducting quantum annealer. We first demonstrate quantitative agreement between quantum annealing and time evolution of the Schrdinger equation in small spin glasses. We then measure dynamics in three-dimensional spin glasses on thousands of qubits, for which classical simulation of many-body quantum dynamics is intractable. We extract critical exponents that clearly distinguish quantum annealing from the slower stochastic dynamics of analogous Monte Carlo algorithms, providing both theoretical and experimental support for large-scale quantum simulation and a scaling advantage in energy optimization.

DOI: 10.1038/s41586-023-05867-2

Source: https://www.nature.com/articles/s41586-023-05867-2