近日，美国哈佛大学的Kang-Kuen Ni及其研究团队取得一项新进展。经过不懈努力，他们揭示原子交换反应中的量子干涉。相关研究成果已于2024年5月16日在国际权威学术期刊《科学》上发表。

据悉，化学键的断裂与形成所经历的化学反应是一个极为动态的量子过程。一个核心问题是，人们是否能在化学反应中保持其相干性，并据此生产出纠缠的产物。

本文旨在通过研究在500 nK低温下发生的2KRb→K₂ + Rb₂反应来深入探讨这一问题，特别聚焦于核自旋自由度。研究人员将磁场降低到自旋-自旋相互作用占主导的程度，成功在纠缠态下制备了KRb中的初始核自旋，并详细表征了反应后核自旋波函数保持的相干性。实验结束时，研究人员观察到了与完全相干状态相一致的干涉图样，这一发现表明，在反应物内部制备的纠缠状态可以通过原子交换过程得到重新分配。

附：英文原文

Title: Quantum interference in atom-exchange reactions

Author: Yi-Xiang Liu, Lingbang Zhu, Jeshurun Luke, J. J. Arfor Houwman, Mark C. Babin, Ming-Guang Hu, Kang-Kuen Ni

Issue&Volume: 2024-05-16

Abstract: Chemical reactions, where bonds break and form, are highly dynamic quantum processes. A fundamental question is whether coherence can be preserved in chemical reactions and then harnessed to generate entangled products. Here we investigated this question by studying the 2KRb → K₂ + Rb₂ reaction at 500 nK, focusing on the nuclear spin degrees of freedom. We prepared the initial nuclear spins in KRb in an entangled state by lowering the magnetic field to where the spin-spin interaction dominates and characterized the preserved coherence in nuclear spin wavefunction after the reaction. We observed an interference pattern that is consistent with full coherence at the end of the reaction, suggesting that entanglement prepared within the reactants could be redistributed through the atom-exchange process.

DOI: 10.1126/science.adl6570

Source: https://www.science.org/doi/10.1126/science.adl6570