近日，浙江大学的王逸璞及其研究团队取得一项新进展。经过不懈努力，他们对非厄米系统中的同步和异步现象进行研究。相关研究成果已于2024年11月4日在国际知名学术期刊《物理评论A》上发表。

在这项工作中，该研究团队研究了一个包含两个耦合玻色子模式的简单非厄米系统中的同步与异步现象。研究人员发现，这样一个开放系统在同步时会向一个更低耗散的状态演化，其中特定对称性的存在，如反宇称-时间（反PT）对称性和PT对称性，会影响同步。

特别地，研究人员表明当反PT对称性破缺或PT对称性未破缺时，由于特征值虚部的简并，会发生异步状态。他们将这种现象称为“简并诱导的异步”。这一发现为在非厄米系统中产生和控制同步与异步提供了新见解。

据悉，同步与异步现象在广泛的自然和人工系统中普遍存在。导致这些现象发生的潜在机制通常很复杂，因此很难把握引起同步或异步的关键因素。此外，现实世界中的系统经常与其周围环境进行能量交换；在非厄米系统中，同步与异步现象尚未被完全理解。

附：英文原文

Title: Synchronization and asynchronization in non-Hermitian systems

Author: Qi Hong, Wen-Xin Wu, Yuan-Peng Peng, Jie Qian, Can-Ming Hu, Yi-Pu Wang

Issue&Volume: 2024/11/04

Abstract: Synchronization and asynchronization are ubiquitous occurrences in a wide range of natural and artificial systems. The underlying mechanisms responsible for these events are typically complex, presenting a considerable difficulty to grasp the crucial elements that cause synchronization or asynchronization. Moreover, real-world systems frequently encounter energy exchanges with their surrounding environment; synchronization and asynchronization in such non-Hermitian systems have not been fully understood. In this work, we study the synchronization and asynchronization phenomena in a simple non-Hermitian system that involves two coupled bosonic modes. We find that such an open system evolves towards a state of lower dissipation as it synchronizes, whereby the existence of particular symmetries, such as anti-parity-time (anti-PT) symmetry and PT symmetry, impact synchronization. Peculiarly, we show that when the anti-PT symmetry is broken or the PT symmetry is unbroken, a state of asynchronization occurs as the result of the degeneracy of imaginary parts of the eigenvalues. We designate this occurrence as “degeneracy-induced asynchronization.” Our findings shed light on generating and controlling synchronization and asynchronization in non-Hermitian systems.

DOI: 10.1103/PhysRevA.110.052201

Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.110.052201