光子晶体中拓扑引致的界面态和边缘态的研究

Topological optical insulator has attracted many research attentions recently. Based on the theory of topological insulator, scientists have successfully demonstrated optical analogy to quantum hall effect and quantum spin hall effect. These topologically induced interface states and edge states of light, immune to the scatterers on the propagating path, will pave a new road to future optical communication system. We are going to explore the physics of photonic crystals with topological characteristics, both theoretically and experimentally. By digging deep into the electron-light analogy, we are going to find new theories to character topological properties of photonic crystals and deterministic conditions for the existences of interface states and edge states. These states will be further constructed utilizing metamaterials and photonic crystals, and their propagation properties will be measured by new microwave experimental methods developed. We will improve photonic crystal platform to have a one-to-one correspondence to tight-binding theory and develop an optical analogy experimental platform to demonstrate and verify condensed matter theory predictions. Our theoretical and experimental study of topologically induced interface states and edge states in photonic crystals will help the realization of new optical communication devices and the development of condensed matter physics.

拓扑光子绝缘体是目前光学研究的热点。通过寻找拓扑绝缘体的光学类比，已经实现了光的量子霍尔效应和自旋量子霍尔效应。拓扑引致的光的界面态和边缘态，不会受传播路径上杂质的影响，具有广泛的应用前景。而能带具有拓扑特性的光子晶体是其中的重要组成部分，但目前的理论框架和实验手段方面仍有很多的空白。本项目拟开展对光子晶体中拓扑引致的界面态和边缘态的研究，包括：1）发展光子晶体能带拓扑性质以及其界面态/边缘态存在条件的新理论；2）微波实验实现拓扑保护的光子晶体界面态/边缘态并测量其传播特性；3）打造与紧束缚近似有一一对应关系的凝聚态理论光子晶体类比实验平台。我们希望通过理论分析，数值模拟和微波实验等多方面研究，利用拓扑绝缘体理论和光学理论及实验的交叉，构建新型的拓扑保护的光学界面态/边缘态，推动新型光通信器件的发展；并利用光子晶体的类比实验平台，验证拓扑绝缘体的凝聚态理论。

拓扑光子绝缘体是目前光学研究的热点。拓扑引致的光的界面态和边缘态，不会受传播路径上杂质的影响，具有广泛的应用前景。受国家自然科学基金的支持，本项目通过理论分析，数值模拟和微波实验等多方面研究，系统的研究了光子晶体体能带的拓扑性质，并用包括Zak相位，谷陈数及赝自旋陈数等在内多个拓扑不变量加以标记。在具有体反转能带性质的光子晶体的界面上，实现了一系列拓扑光子晶体界面态：包括3种体Zak相位反转的确定性界面态；构建了光学赝自旋并和电子Kramers对进行类比，在光子晶体平台实现了光学量子自旋霍尔效应；实现谷自旋光学单向传输。我们的微波实验，实现了拓扑保护的光子晶体界面态，并测量其局域特性乃至传播特性。同时，利用光子晶体能带的调控，实现了包括超透明材料，超薄透射隐身器件等多项重要工作。我们相信，利用拓扑绝缘体理论和光学理论及实验的交叉，构建新型的拓扑保护的光学界面态/边缘态，推动新型光通信器件的发展。