Emerging electronic states at boundaries and domain walls in quantum materials
Abstract/Contents
- Abstract
- Boundaries and domain walls in condensed matter often host unique electronic states that are distinct from those living inside the bulk. Their intriguing physics and diverse application potentials have attracted growing research effort on codifying the relevant emergent laws, whereas their complex and low-dimensional nature constantly calls for novel characterization techniques. Scanning Microwave Impedance Microscopy (MIM) characterizes local electrical response (complex permittivity) by probing microwave tip-sample admittance in the meso- to microscopic scale. It has matured in the past decade and has become a powerful tool for studying these emerging electronic states in real space, highly complementary to existing tools working in atomic scale or momentum space. In this dissertation I will first give a scientific overview of the field (Chapter 1), followed by a brief introduction to MIM, with a focus on the fundamental principles and recent developments (Chapter 2). I will then present five scientific studies made possible by MIM, which can be grouped into two categories, namely 1D edge states at solid-vacuum boundaries in 2D systems (Chapter 3), and order-parameter domain walls embedded in a 3D solid (Chapter 4). Chapter 3 contains the discovery of unexpected edge conduction in HgTe/CdTe quantum wells in the presence of a strong magnetic field, an unconventional correlation between quantum Hall transport quantization and bulk Landau level filling in gated graphene devices, and edge-bulk conductivity contrast in magnetic modulation doped Cr-(Bi, Sb)Te films in the quantum anomalous Hall regime. Chapter 4 includes the signature of charge-order domain walls with enhanced conductivity in a layered magnanite, and the establishment of neodymium iridate as the first experimental realization of a magnetic insulator with metallic magnetic domain walls.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2016 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Ma, Eric Yue |
|---|---|
| Associated with | Stanford University, Department of Applied Physics. |
| Primary advisor | Shen, Zhi-Xun |
| Thesis advisor | Shen, Zhi-Xun |
| Thesis advisor | Goldhaber-Gordon, David, 1972- |
| Thesis advisor | Moler, Kathryn A |
| Advisor | Goldhaber-Gordon, David, 1972- |
| Advisor | Moler, Kathryn A |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Eric Yue Ma. |
|---|---|
| Note | Submitted to the Department of Applied Physics. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2016. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2016 by Yue Ma
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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