二维拓扑体系及过渡金属薄膜的能带及输运特性研究
发布时间：2022-10-17 14:43
拓扑概念的引入极大地丰富了传统的凝聚态物理。从体材料角度,根据能带拓扑数对物质态进行分类的标准被引入,量子霍尔效应、量子反常霍尔效应、拓扑绝缘体等新物质态被提出,超越了传统的朗道范式,并且其在金属领域的推广不仅解释了反常/自旋霍尔效应,还引出了外尔半金属这一物质态;在有限尺寸体系中,绝缘体的拓扑性体现在鲁棒的金属性边界态上,提供了一种难以被杂质散射的低维、低能量耗散电子态;虽然拓扑性对材料的细节特性不敏感,然而,不同的拓扑界面态呈现出一些依赖于材料特性的电子、自旋输运行为,为基础研究和实际应用提供了很好的平台。本论文中,我们发现了一种朗道对称破缺协助产生的新拓扑物质态的迹象,即电荷密度波协助产生的三维量子霍尔效应（第一章）,提出两种实现量子反常霍尔效应的新机制,一者基于面内磁化,二者由库仑相互作用诱导产生（第二、三章）,研究了基于量子谷霍尔效应和量子反常霍尔效应的拓扑界面态的输运特性（第四章）,并构造过渡金属单原子层的模型哈密顿量,为后续研究其输运特性打下基础（第五章）。引入拓扑概念的最重要的因素之一是量子霍尔效应的发现,为了解释这一现象而提出的各种理论成为后续拓扑能带理论的基础。因此...
【文章页数】：151 页
【学位级别】：博士
【文章目录】：
摘要
ABSTRACT
Nomenclature
Chapter 1 Introduction
1.1 Quantum Hall Effect (QHE)
1.1.1 Landau levels
1.1.2 Pumping
1.1.3 Edge States
1.1.4 Periodic Potential
1.2 Topological Phases in Atomic Crystal Layers
1.2.1 Honeycomb Lattice and the Haldane Model
1.2.2 Haldane's Model with Spin: Graphene as Topological Insulator (TI)
1.3 Three-dimensional (3D) Topological Phases
1.3.1 3D TI
1.3.2 3D QHE
Chapter 2 QAHE from In-plane Magnetization
2.1 Review of QAHE from Out-of-plane Magnetization
2.1.1 Graphene with Magnetism and Rashba Spin-orbit Coupling (SOC)
2.1.2 3D-TI Thin Films with Magnetic Doping
2.2 Symmetry Difference: Out-of-plane vs In-plane Magnetization
2.3 Buckled Lattices of Group-IV Elements
2.3.1 Tight-binding Hamiltonian
2.3.2 Monolayer Case
2.3.3 Multilayer Cases
2.4 Buckled Lattice of Group-V Elements
2.4.1 Model and Electronic Structure
2.4.2 Role of SOC Strength on Topological Phases
2.4.3 Role of Out-of-plane Component of Magnetization and Strain
2.5 Summary and Outlook
Chapter 3 Valley Engineering and Spontaneous QAHE
3.1 Inter-valley Coupling
3.1.1 Superlattice with C_(3v) Symmetry and Quadratic Band Crossing
3.1.2 Superlattices with C_(6v) and C_(2v) Symmetries
3.1.3 Generalized Effective Hamiltonian from Symmetry Analysis
3.2 Quadratic Band Crossing with Coulomb Interaction
3.2.1 Instability of Fermi Point Driven by Interaction
3.2.2 Quadratic Band Crossing on Kagome Lattice Model
3.2.3 Spontaneous QAHE Driven by Interaction
3.2.4 Phase Transition
3.3 Summary and Outlook
Chapter 4 Zero-line Mode (ZLM)
4.1 Review of ZLM Based on QVHE
4.1.1 Electronic Structures
4.1.2 Electronic Transport Properties of Topological ZLMs
4.2 ZLM from QAHE with Out-of-plane Magnetization
4.2.1 Motivation
4.2.2 Electronic Structures
4.2.3 Electronic Transport Properties
4.3 ZLMs from QAHE with In-plane Magnetization
4.3.1 Motivation
4.3.2 Model and Electronic Structure of ZLMs
4.3.3 Current Partition at Y-shape Junction
4.3.4 Network and Flat Bands
4.4 Summary and Outlook
Chapter 5 Electronic Structures of Transition Metal Monolayers
5.1 Introduction
5.2 Model and Formalism
5.2.1 Tight-binding Model
5.2.2 First-principles Calculations
5.3 Energy Bands and Fitting Parameters
5.3.1 Lattice Constants
5.3.2 3d Transition-metal Monolayers
5.3.3 5d Transition-metal Monolayers
5.4 Fitting Method and Fitting Results
5.4.1 Nonlinear Fitting
5.4.2 Summarize of the Fitting Results
5.5 Summary and Outlook
Chapter 6 Summary and Discussion
References
致谢
Publications
【参考文献】：
期刊论文
[1]A review of the growth and structures of silicene on Ag（111）[J]. 吴克辉. Chinese Physics B. 2015(08)
本文编号：3692262
【文章页数】：151 页
【学位级别】：博士
【文章目录】：
摘要
ABSTRACT
Nomenclature
Chapter 1 Introduction
1.1 Quantum Hall Effect (QHE)
1.1.1 Landau levels
1.1.2 Pumping
1.1.3 Edge States
1.1.4 Periodic Potential
1.2 Topological Phases in Atomic Crystal Layers
1.2.1 Honeycomb Lattice and the Haldane Model
1.2.2 Haldane's Model with Spin: Graphene as Topological Insulator (TI)
1.3 Three-dimensional (3D) Topological Phases
1.3.1 3D TI
1.3.2 3D QHE
Chapter 2 QAHE from In-plane Magnetization
2.1 Review of QAHE from Out-of-plane Magnetization
2.1.1 Graphene with Magnetism and Rashba Spin-orbit Coupling (SOC)
2.1.2 3D-TI Thin Films with Magnetic Doping
2.2 Symmetry Difference: Out-of-plane vs In-plane Magnetization
2.3 Buckled Lattices of Group-IV Elements
2.3.1 Tight-binding Hamiltonian
2.3.2 Monolayer Case
2.3.3 Multilayer Cases
2.4 Buckled Lattice of Group-V Elements
2.4.1 Model and Electronic Structure
2.4.2 Role of SOC Strength on Topological Phases
2.4.3 Role of Out-of-plane Component of Magnetization and Strain
2.5 Summary and Outlook
Chapter 3 Valley Engineering and Spontaneous QAHE
3.1 Inter-valley Coupling
3.1.1 Superlattice with C_(3v) Symmetry and Quadratic Band Crossing
3.1.2 Superlattices with C_(6v) and C_(2v) Symmetries
3.1.3 Generalized Effective Hamiltonian from Symmetry Analysis
3.2 Quadratic Band Crossing with Coulomb Interaction
3.2.1 Instability of Fermi Point Driven by Interaction
3.2.2 Quadratic Band Crossing on Kagome Lattice Model
3.2.3 Spontaneous QAHE Driven by Interaction
3.2.4 Phase Transition
3.3 Summary and Outlook
Chapter 4 Zero-line Mode (ZLM)
4.1 Review of ZLM Based on QVHE
4.1.1 Electronic Structures
4.1.2 Electronic Transport Properties of Topological ZLMs
4.2 ZLM from QAHE with Out-of-plane Magnetization
4.2.1 Motivation
4.2.2 Electronic Structures
4.2.3 Electronic Transport Properties
4.3 ZLMs from QAHE with In-plane Magnetization
4.3.1 Motivation
4.3.2 Model and Electronic Structure of ZLMs
4.3.3 Current Partition at Y-shape Junction
4.3.4 Network and Flat Bands
4.4 Summary and Outlook
Chapter 5 Electronic Structures of Transition Metal Monolayers
5.1 Introduction
5.2 Model and Formalism
5.2.1 Tight-binding Model
5.2.2 First-principles Calculations
5.3 Energy Bands and Fitting Parameters
5.3.1 Lattice Constants
5.3.2 3d Transition-metal Monolayers
5.3.3 5d Transition-metal Monolayers
5.4 Fitting Method and Fitting Results
5.4.1 Nonlinear Fitting
5.4.2 Summarize of the Fitting Results
5.5 Summary and Outlook
Chapter 6 Summary and Discussion
References
致谢
Publications
【参考文献】：
期刊论文
[1]A review of the growth and structures of silicene on Ag（111）[J]. 吴克辉. Chinese Physics B. 2015(08)
本文编号：3692262
本文链接：https://www.wllwen.com/kejilunwen/wulilw/3692262.html
