论文标题
第一原理计算非热光子晶体的拓扑不变性
First Principles Calculation of Topological Invariants of non-Hermitian Photonic Crystals
论文作者
论文摘要
材料平台的Chern拓扑数通常是根据浆果曲率编写的，这取决于系统的正常模式。在这里，我们使用尺度不变的绿色功能方法从第一原理中确定光子晶体的拓扑不变性。提出的形式主义不需要计算光子带结构，并且可以使用标准平面波扩展获得的操作员轻松实现。此外，可以证明该理论可以很容易地应用于具有有损或粘性材料（例如平等时代对称的光子晶体）的非铁感光子晶体的拓扑阶段的分类。
The Chern topological numbers of a material platform are usually written in terms of the Berry curvature, which depends on the normal modes of the system. Here, we use a gauge invariant Green's function method to determine from first principles the topological invariants of photonic crystals. The proposed formalism does not require the calculation of the photonic band-structure, and can be easily implemented using the operators obtained with a standard plane-wave expansion. Furthermore, it is shown that the theory can be readily applied to the classification of topological phases of non-Hermitian photonic crystals with lossy or gainy materials, e.g., parity-time symmetric photonic crystals.
