检索结果-南通市图书馆

Stiefel–Whitney classes and topological phases in band theory

Chinese Physics B 2019年第11期28卷 1-17页

作者： Junyeong Ahn Sungjoon Park Dongwook Kim Youngkuk Kim bohm-jung yang Department of Physics and Astronomy Seoul National UniversitySeoul 08826Korea Center for Correlated Electron Systems Institute for Basic Science(IBS)Seoul 08826Korea Center for Theoretical Physics(CTP) Seoul National UniversitySeoul 08826Korea

We review the recent progress in the study of topological phases in systems with space–time inversion symmetry *** an anti-unitary symmetry which is local in momentum space and satisfies I2 ST= 1 such as PT in two dimensions(2 D)and three dimensions(3 D) without spin–orbit coupling and C2 T in 2 D with or without spin–orbit coupling, where P, T, C2 indicate the inversion, time-reversal, and two-fold rotation symmetries, respectively. Under IST, the Hamiltonian and the periodic part of the Bloch wave function can be constrained to be real-valued, which makes the Berry curvature and the Chern number vanish. In this class of systems, gapped band structures of real wave functions can be topologically distinguished by the Stiefel–Whitney numbers instead. The first and second Stiefel–Whitney numbers w1 and w2, respectively,are the corresponding invariants in 1 D and 2 D, which are equivalent to the quantized Berry phase and the Z2 monopole charge, respectively. We first describe the topological phases characterized by the first Stiefel–Whitney number, including1 D topological insulators with quantized charge polarization, 2 D Dirac semimetals, and 3 D nodal line semimetals. Next we review how the second Stiefel–Whitney class characterizes the 3 D nodal line semimetals carrying a Z2 monopole *** particular, we explain how the second Stiefel–Whitney number w2, the Z2 monopole charge, and the linking number between nodal lines are related. Finally, we review the properties of 2 D and 3 D topological insulators characterized by the nontrivial second Stiefel Whitney class.

关键词： topological semimetal

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Magnetic wallpaper Dirac fermions and topological magnetic Dirac insulators

引用

npj Computational Materials 2023年第1期9卷 1695-1702页

作者： Yoonseok Hwang Yuting Qian Junha Kang Jehyun Lee Dongchoon Ryu Hong Chul Choi bohm-jung yang Center for Correlated Electron Systems Institute for Basic Science(IBS)Seoul 08826Korea Department of Physics and Astronomy Seoul National UniversitySeoul 08826Korea Center for Theoretical Physics(CTP) Seoul National UniversitySeoul 08826Korea

Topological crystalline insulators(TCIs)can host anomalous surface states which inherits the characteristics of crystalline symmetry that protects the bulk ***,the diversity of magnetic crystalline symmetries indicates the potential for novel magnetic TCIs with distinct surface ***,we propose a topological magnetic Dirac insulator(TMDI),whose two-dimensional surface hosts fourfold-degenerate Dirac fermions protected by either the p'_(c)4mm or p40 g0 m magnetic wallpaper *** bulk topology of TMDIs is protected by diagonal mirror symmetries,which give chiral dispersion of surface Dirac fermions and mirror-protected hinge *** propose candidate materials for TMDIs including Nd_(4)Te_(8)Cl_(4)O_(2)0 and DyB_(4) based on first-principles calculations,and construct a general scheme for searching TMDIs using the space group of paramagnetic parent *** theoretical discovery of TMDIs will facilitate future research on magnetic TCIs and illustrate a distinct way to achieve anomalous surface states in magnetic crystals.

关键词： Dirac topological protected

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：