近日，英国牛津大学的Chao He&An Aloysius Wang及其研究团队取得一项新进展。他们实现了复杂介质中光学斯格明子的拓扑保护。相关研究成果已于2024年11月22日在国际知名学术期刊《光：科学与应用》上发表。

该研究团队通过证明斯格明子的拓扑性质源于其边界结构，并且根据对偶性，只要扰动满足未受扰动斯格明子的相关边界条件，就能抵御空间变化的扰动，从而精确地量化了这种鲁棒性。接着，研究人员提供了实验证据，验证了旁轴斯格明子光束在复杂极化像差背景下的这种鲁棒性。

这项研究工作为处理斯格明子场的各种扰动提供了一个框架，并在广义上保证了其鲁棒性。这反过来对明确利用斯格明子拓扑性质的应用产生了影响，特别是为光学斯格明子在通信和计算中的应用提供了基础支撑。

据悉，光学斯格明子具备许多重要特性，使其成为高密度数据应用的理想单元，这些特性包括能够通过离散的拓扑数携带数字信息，以及空间变化极化与其他维度的独立性。更重要的是，光学斯格明子的拓扑性质启发式地表明其对扰动具有很强的鲁棒性，这对于在嘈杂环境中可靠地传输信息至关重要。然而，对光学斯格明子拓扑鲁棒性的研究仍处于初级阶段。

附：英文原文

Title: Topological protection of optical skyrmions through complex media

Author: Wang, An Aloysius, Zhao, Zimo, Ma, Yifei, Cai, Yuxi, Zhang, Runchen, Shang, Xiaoyi, Zhang, Yunqi, Qin, Ji, Pong, Zhi-Kai, Marozsk, Td, Chen, Binguo, He, Honghui, Luo, Lin, Booth, Martin J., Elston, Steve J., Morris, Stephen M., He, Chao

Issue&Volume: 2024-11-22

Abstract: Optical Skyrmions have many important properties that make them ideal units for high-density data applications, including the ability to carry digital information through a discrete topological number and the independence of spatially varying polarization to other dimensions. More importantly, the topological nature of the optical Skyrmion heuristically suggests a strong degree of robustness to perturbations, which is crucial for reliably carrying information in noisy environments. However, the study of the topological robustness of optical Skyrmions is still in its infancy. Here, we quantify this robustness precisely by proving that the topological nature of the Skyrmion arises from its structure on the boundary and, by duality, is resilient to spatially varying perturbations provided they respect the relevant boundary conditions of the unperturbed Skyrmion. We then present experimental evidence validating this robustness in the context of paraxial Skyrmion beams against complex polarization aberrations. Our work provides a framework for handling various perturbations of Skyrmion fields and offers guarantees of robustness in a general sense. This, in turn, has implications for applications of the Skyrmion where their topological nature is exploited explicitly, and, in particular, provides an underpinning for the use of optical Skyrmions in communications and computing.

DOI: 10.1038/s41377-024-01659-z

Source: https://www.nature.com/articles/s41377-024-01659-z