论文标题
在电路中观察到的角状态的非铁皮皮肤效应和拓扑定位的竞争
Competition of non-Hermitian skin effect and topological localization of corner states observed in circuits
论文作者
论文摘要
探索非炎性系统中的拓扑阶段引起了最近的关注。一个有趣的问题是拓扑边缘状态如何与非铁皮皮肤效应竞争。在这里，我们报告了二维非核菱形蜂窝电路中角状态的实验观察。我们通过在两个节点之间引入电流方向分辨的电容来构建非逆局和非热电路，这取决于电流方向。因此，皮肤作用是由于非股骨能力而出现的，并且在将角状态拖入大量时占了上风。采用广义布里鲁因区域定义的非Bloch绕组数以表征拓扑相变。有趣的是，我们发现非bloch $ Z_2 $浆果阶段可以作为描述非热拓扑的不变性。通过调整非重新性参数，我们观察到在菱形晶格的两个急性角度出现的角状态的不平衡分布，左角状态的定位长度随着非二脂肪的程度呈指数增长。
Exploring topological phases in non-Hermitian systems has attracted significant recent attention. One intriguing question is how topological edge states compete with the non-Hermitian skin effect. Here, we report the experimental observation of corner states in a two-dimensional non-reciprocal rhombus honeycomb electric circuit. We construct non-reciprocal and non-Hermitian circuits by introducing current-direction resolved capacitance between two nodes depends on the current direction. Skin effect thus emerges due to the non-reciprocity and prevails in dragging the corner state into the bulk. The non-Bloch winding number defined in generalized Brillouin zone is adopted to characterize the topological phase transition. Interestingly, we find that the non-Bloch $Z_2$ Berry phase can serve as an invariant to describe the non-Hermitian topology. By tuning the non-reciprocal parameter, we observe unbalanced distribution of corner states emerging on two acute angles of the rhombus lattice, with the localization length of the left corner state increasing exponentially with the degree of non-reciprocity.
