Braiding topology of non-Hermitian open-boundary bands,Physical Review B

当前位置： X-MOL 学术 › Phys. Rev. B › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Braiding topology of non-Hermitian open-boundary bands
Physical Review B ( IF 3.2 ) Pub Date : 2024-09-05 , DOI: 10.1103/physrevb.110.l121401
Yongxu Fu ₁ , Yi Zhang ₁

Affiliation

There has been much recent interest and progress on topological structures of the non-Hermitian Bloch bands. Here, we study the topological structures of non-Bloch bands of non-Hermitian multiband quantum systems under open boundary conditions, which has received limited attention in prior studies. Using a continuity criterion and an efficient sub-generalized Brillouin zone (sub-GBZ) algorithm, we establish a homotopic characterization—braiding topology, e.g., characterized by the band's total vorticity—for open-boundary bands and sub-GBZs. Such topological identification is robust without topological transition and emergent degenerate points, such as exceptional points. We further analyze the transition's impact on bands and spectral flows, including interesting properties unique to open boundaries, and numerically demonstrate our conclusions with tight-binding model examples. We unveil a crucial insight that open-boundary bands interchange their portions after encountering certain exceptional points. Our results enrich the foundational understanding of topological characterizations for generic non-Hermitian quantum systems.

中文翻译：

非厄米开放边界带的编织拓扑

最近人们对非厄米布洛赫带的拓扑结构产生了很多兴趣并取得了进展。在这里，我们研究开放边界条件下非厄米多带量子系统的非布洛赫能带的拓扑结构，这在先前的研究中受到的关注有限。使用连续性准则和高效的次广义布里渊区（sub-GBZ）算法，我们为开放边界带和sub-GBZ建立了同伦表征——编织拓扑，例如，以带的总涡度为特征。这种拓扑识别是鲁棒的，没有拓扑转变和出现的简并点，例如异常点。我们进一步分析了跃迁对能带和光谱流的影响，包括开放边界特有的有趣特性，并用紧束缚模型示例在数值上证明了我们的结论。我们揭示了一个重要的见解，即开放边界带在遇到某些特殊点后会交换其部分。我们的结果丰富了对通用非厄米量子系统拓扑表征的基础理解。

更新日期：2024-09-05

点击分享查看原文

点击收藏

公开下载

阅读更多本刊新发论文本刊介绍/投稿指南