近日，奥地利维也纳大学的Uroš Deli?及其研究团队取得一项新进展。经过不懈努力，他们揭示光学耦合纳米粒子的非厄米动力学和非互易性。相关研究成果已于2024年7月25日在国际知名学术期刊《自然—物理学》上发表。

该研究团队利用这种可调谐性来研究两个非相互作用和非线性相互作用的纳米粒子的集体非厄米动力学。研究人员观察到宇称时间对称性破缺，并且在足够强的耦合下，观察到粒子沿稳定极限环运动的集体机械激光跃迁。这项工作开辟了非平衡多粒子集体效应的研究途径，通过镊子阵列中单个位点的动态控制来调节。

据悉，在光子、原子、电和光机械平台中观察到的非厄米动力学在传感应用和信号处理方面具有巨大的潜力。近年来，悬浮纳米粒子之间的完全可调谐非互易光相互作用已被证实。

附：英文原文

Title: Non-Hermitian dynamics and non-reciprocity of optically coupled nanoparticles

Author: Reisenbauer, Manuel, Rudolph, Henning, Egyed, Livia, Hornberger, Klaus, Zasedatelev, Anton V., Abuzarli, Murad, Stickler, Benjamin A., Deli, Uro

Issue&Volume: 2024-07-25

Abstract: Non-Hermitian dynamics, as observed in photonic, atomic, electrical and optomechanical platforms, holds great potential for sensing applications and signal processing. Recently, fully tuneable non-reciprocal optical interaction has been demonstrated between levitated nanoparticles. Here we use this tunability to investigate the collective non-Hermitian dynamics of two non-reciprocally and nonlinearly interacting nanoparticles. We observe parity–time symmetry breaking and, for sufficiently strong coupling, a collective mechanical lasing transition in which the particles move along stable limit cycles. This work opens up a research avenue of non-equilibrium multi-particle collective effects, tailored by the dynamic control of individual sites in a tweezer array.

DOI: 10.1038/s41567-024-02589-8

Source: https://www.nature.com/articles/s41567-024-02589-8