论文标题
非热界光谱绕组
Non-Hermitian boundary spectral winding
论文作者
论文摘要
复杂特征力的光谱绕组代表了非热式系统中独特的拓扑方面，在开放边界条件下（OBC）在一维（1D）系统中消失。在这项工作中，我们发现了OBC下二维非炎症系统中的边界频谱绕组，源自Hermitian边界定位与非富米特非雷神泵送之间的相互作用。这种非平凡的边界拓扑在具有三角形几何形状的非热呼吸kagome模型中得到了证明，其1D边界在周期性的边界条件下模仿了具有非平凡光谱绕组的1D非热系统。在梯形几何形状中，这种边界频谱绕组甚至可以与边缘状态的角积累共存，而不是沿三角形几何形状的1D边界的延伸态。 OBC类型的杂交皮肤效应也可能在梯形几何形状中出现，提供边界光谱绕组完全消失。通过研究绿色的功能，我们揭示了可以从系统的拓扑响应到局部驾驶场的拓扑响应来检测到边界频谱绕组，从而提供了一种实现的方法来提取实验研究的非平凡边界拓扑。
Spectral winding of complex eigenenergies represents a topological aspect unique in non-Hermitian systems, which vanishes in one-dimensional (1D) systems under the open boundary conditions (OBC). In this work, we discover a boundary spectral winding in two-dimensional non-Hermitian systems under the OBC, originating from the interplay between Hermitian boundary localization and non-Hermitian non-reciprocal pumping. Such a nontrivial boundary topology is demonstrated in a non-Hermitian breathing Kagome model with a triangle geometry, whose 1D boundary mimics a 1D non-Hermitian system under the periodic boundary conditions with nontrivial spectral winding. In a trapezoidal geometry, such a boundary spectral winding can even co-exist with corner accumulation of edge states, instead of extended ones along 1D boundary of a triangle geometry. An OBC type of hybrid skin-topological effect may also emerge in a trapezoidal geometry, provided the boundary spectral winding completely vanishes. By studying the Green's function, we unveil that the boundary spectral winding can be detected from a topological response of the system to a local driving field, offering a realistic method to extract the nontrivial boundary topology for experimental studies.
