美国加州大学伯克利分校Dan M. Stamper-Kurn团队研究了介观原子阵列中的光力学自组织。2025年5月26日出版的《自然—物理学》杂志发表了这项成果。

增加系统中的粒子数量通常会导致其性质发生质的变化，例如对称性的破坏和相变的出现。这使得宏观系统与其各个微观组成部分有着根本的不同。位于这些极端之间的介观系统表现出微观波动，这些波动会影响更长尺度上的行为，从而导致临界现象和动力学。因此，追踪受控介观系统的性质可以帮助弥合少体微观系统的精确描述和多体系统的涌现描述之间的差距。 

研究组使用光学腔内的冷原子阵列探索光机自组织相变的介观特征。通过精确设计原子-腔相互作用，揭示了临界行为如何取决于原子数，识别了自组织状态下的特征动力学行为，并观察到临界点处的有限光机磁化率。这些发现深化了研究组对介观系统中相变的粒子数和时间分辨特性的理解。

附：英文原文

Title: Optomechanical self-organization in a mesoscopic atom array

Author: Ho, Jacquelyn, Lu, Yue-Hui, Xiang, Tai, Rusconi, Cosimo C., Masson, Stuart J., Asenjo-Garcia, Ana, Yan, Zhenjie, Stamper-Kurn, Dan M.

Issue&Volume: 2025-05-26

Abstract: Increasing the number of particles in a system often leads to qualitative changes in its properties, such as breaking of symmetries and the appearance of phase transitions. This renders a macroscopic system fundamentally different from its individual microscopic constituents. Lying between these extremes, mesoscopic systems exhibit microscopic fluctuations that influence behaviour on longer length scales, leading to critical phenomena and dynamics. Therefore, tracing the properties of well-controlled mesoscopic systems can help bridge the gap between an exact description of few-body microscopic systems and the emergent description of many-body systems. Here we explore the mesoscopic signatures of an optomechanical self-organization phase transition using arrays of cold atoms inside an optical cavity. By precisely engineering atom–cavity interactions, we reveal how critical behaviour depends on the atom number, identify characteristic dynamical behaviours in the self-organized regime and observe a finite optomechanical susceptibility at the critical point. These findings advance our understanding of particle-number- and time-resolved properties of phase transitions in mesoscopic systems.

DOI: 10.1038/s41567-025-02916-7

Source: https://www.nature.com/articles/s41567-025-02916-7