Generalized Wen-Zee terms
Generalized Wen-Zee terms
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DOI：
10.1103/physrevb.99.205120
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发表时间：
2018-07
影响因子：
3.7
通讯作者：
Bolin Han;Huajia Wang;P. Ye
中科院分区：
文献类型：
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作者：
Bolin Han;Huajia Wang;P. Ye
受具有空间对称性(如晶格旋转)和内部对称性(如自旋旋转)的对称性保护拓扑相(SPT)的启发，我们提出了一类奇异拓扑项，它推广了著名的量子霍尔系统的Wen-Zee拓扑项[X.-G.wen和A.Zee，Phys.莱特牧师。69,953(1992)]。这些广义的Wen-Zee项被表示为不同维度的自旋连接和通常的规范场(1-形式或更高形式)的楔积。为了探索SPT阶数，我们在外部插入对称性扭曲，如具有离散内部对称性的域壁和具有非平凡黎曼曲率的几何缺陷的倾斜。然后，广义的文采项简单地告诉我们SPT是如何响应这些对称扭曲的。对这些奇异的拓扑学术语进行分类，从而在本框架内对SPT进行了完整的分类和描述。我们还提出了SPT低能场理论，从该理论出发，我们将广义的Wen-Zee项推导为拓扑响应作用。在文采论文的摘要之后，我们的工作丰富了实现电磁和引力统一的凝聚态的替代可能性。
Motivated by symmetry-protected topological phases (SPTs) with both spatial symmetry (e.g., lattice rotation) and internal symmetry (e.g., spin rotation), we propose a class of exotic topological terms, which generalize the well-known Wen-Zee topological terms of quantum Hall systems [X.-G. Wen and A. Zee, Phys. Rev. Lett. 69, 953 (1992)]. These generalized Wen-Zee terms are expressed as wedge product of spin connection and usual gauge fields (1-form or higher) in various dimensions. In order to probe SPT orders, we externally insert symmetry twists such as domain walls of discrete internal symmetry and disclinations that are geometric defects with nontrivial Riemann curvature. Then, generalized Wen-Zee terms simply tell us how SPTs respond to those symmetry twists. Classifying these exotic topological terms thus leads to a complete classification and characterization of SPTs within the present framework. We also propose SPT low-energy field theories, from which generalized Wen-Zee terms are deduced as topological response actions. Following the Abstract of the Wen-Zee paper, our work enriches alternative possibilities of condensed-matter realization of unification of electromagnetism and gravity.