近日，德国乌尔姆大学的Johannes Hecker Denschlag&Shinsuke Haze及其研究团队取得一项新进展。经过不懈努力，他们利用费什巴赫共振控制少体反应途径。相关研究成果已于2025年1月9日在国际知名学术期刊《自然—物理学》上发表。

该研究团队展示了一种方法，能够在囚禁冷原子云中，相干地引导三体复合过程的反应通量跨越不同的产物自旋通道。研究人员利用磁可调谐的费什巴赫共振，以受控方式将特定的自旋态混合到反应碰撞复合物中。这使他们能够控制进入混合自旋通道的反应通量，从而改变反应产物。

研究人员还研究了埃菲莫夫共振对反应动力学的影响，观察到三体复合的整体增强，而不偏向特定的反应通道。这一控制方案可以扩展到其他反应过程，并且可以与其他方法（如反应路径的量子干涉）相结合，以实现对少体反应的进一步调控能力。

据悉，在量子层面实现对化学反应的控制是冷化学和超冷化学的核心目标。

附：英文原文

Title: Controlling few-body reaction pathways using a Feshbach resonance

Author: Haze, Shinsuke, Li, Jing-Lun, Dorer, Dominik, DIncao, Jos P., Julienne, Paul S., Tiemann, Eberhard, Dei, Markus, Hecker Denschlag, Johannes

Issue&Volume: 2025-01-09

Abstract: Gaining control over chemical reactions at the quantum level is a central goal of cold and ultracold chemistry. Here we demonstrate a method for coherently steering the reaction flux across different product spin channels for a three-body recombination process in a cloud of trapped cold atoms. We use a magnetically tunable Feshbach resonance to admix, in a controlled way, a specific spin state to the reacting collision complex. This allows us to control the reaction flux into the admixed spin channel, which can be used to alter the reaction products. We also investigate the influence of an Efimov resonance on the reaction dynamics, observing a global enhancement of three-body recombination without favouring particular reaction channels. Our control scheme can be extended to other reaction processes and could be combined with other methods, such as quantum interference of reaction paths, to achieve further tuning capabilities of few-body reactions.

DOI: 10.1038/s41567-024-02726-3

Source: https://www.nature.com/articles/s41567-024-02726-