Floquet光子体系中含时拓扑模的研究

拓扑光子学为类比满足拓扑绝缘体中非平庸能带色散关系而设计格点模型和材料排布以获得人为地控制光场的传播，为光场调控提供了新颖途径。它是基于静态拓扑绝缘体展开的被动调控研究，研究表明引入周期性驱动的Floquet光子拓扑绝缘体可实现驱动型非平庸的主动调控，该方法可实现丰富特征的准能带以得到更多的拓扑模式。本项目拟引入周期性驱动调制开展受时间驱动拓扑模式的研究，对SSH拓扑模型施加周期调制的改进，研究包含驱动频率和规范特征的Floquet拓扑量子体系，采用周期性弯曲伪表面等离激元的Floquet波导阵列开展反常拓扑π模的实验研究。本项目将解决不同驱动频率的准能带分析和拓扑不变量的计算、反常拓扑π模的激发、反常拓扑相的驱动频率及Floquet规范的关联、有限尺寸效应下拓扑相的非绝热消去工程应用四个关键科学问题。项目结果将为新型光子二极管、抗电磁信号串扰器和陈数测量器等集成器件提供有力的理论支持。

Topological photonics is a rapidly-emerging field of research in which geometrical and topological ideas are exploited to design and control the behavior of light. However the traditional photonics edge mode in the topological insulators is passive mode, recent research shows that the introduction of periodic-driving Floquet photonics topological insulators can realize active control, and periodically driven approach can achieve large number of Chern number corresponding to more topologic modes. Thanks to the flexibility and diversity of photonics systems, this field is also opening up new opportunities to realise exotic topological models and to probe and exploit topological effects in new ways. Periodically-driven topological phases have attracted considerable attentions in condensed matters, but experimental demonstration of such driven quantum systems with engineered topological phases remains a great challenge. In this proposal, a photonic Floquet simulator (PFS) was designed and systematically investigated to study engineered topological phases in a periodically-driven Su-Schrieffer-Heeger model. The PFS was composed of an ultra-thin coupled microwave waveguide array with periodically-bending profiles, and was thoroughly tested the quantum transition from the adiabatic limit (slow-driving) to the high-frequency limit (fast-driving), and then, extend to design the integrated photonics devices. The results of the project will provides strong theoretical support for the new photonic diode, anti-electromagnetic signal crosstalk and Chern number measuring devices.