Floquet Chern insulators of light
Floquet Chern insulators of light
复制标题
DOI：
10.1038/s41467-019-12231-4
复制
发表时间：
2019-09-13
影响因子：
16.6
通讯作者：
Zhen, Bo
中科院分区：
文献类型：
--
作者：
He, Li;Addison, Zachariah;Zhen, Bo
在光学系统中实现拓扑保护的强健传输最近引起了人们的极大兴趣。大多数研究的拓扑光子结构都可以通过求解静态线性系统的麦克斯韦方程的本征值问题来理解。在这里，我们将拓扑相扩展到动态驱动系统中，实现了非线性光子晶体中光的Floquet-Chen绝缘体。具体地说，我们首先介绍了驱动的二维光子晶体中的Floquet本征值问题。然后我们定义了与Floquite带相关的拓扑不变量，并证明了通过驱动场打破时间反转对称性可以打开非零陈数的拓扑带隙。最后，我们用数值方法证明了在非互易单向输运的Floquite陈氏绝缘子和普通绝缘子之间的界面上存在手征边态。我们的工作为进一步探索驱动光学系统中的拓扑相及其光电子学应用奠定了基础。
Achieving topologically-protected robust transport in optical systems has recently been of great interest. Most studied topological photonic structures can be understood by solving the eigenvalue problem of Maxwell's equations for static linear systems. Here, we extend topological phases into dynamically driven systems and achieve a Floquet Chern insulator of light in nonlinear photonic crystals (PhCs). Specifically, we start by presenting the Floquet eigenvalue problem in driven two-dimensional PhCs. We then define topological invariant associated with Floquet bands, and show that topological band gaps with non-zero Chern number can be opened by breaking time-reversal symmetry through the driving field. Finally, we numerically demonstrate the existence of chiral edge states at the interfaces between a Floquet Chern insulator and normal insulators, where the transport is non-reciprocal and unidirectional. Our work paves the way to further exploring topological phases in driven optical systems and their optoelectronic applications.