Broken rotational symmetry in iron based superconductors
Abstract/Contents
- Abstract
- High-temperature superconductivity often emerges in the proximity of a symmetry-breaking ground state in strongly interacting electronic materials. In the case of the superconducting iron pnictides, in addition to the antiferromagnetic ground state of the parent compounds, a ubiquitous but small structural distortion breaks the crystal C4 rotational symmetry in the underdoped part of the phase diagram. It has been proposed that this structural transition is driven by an electronic nematic phase transition, below which the electronic system spontaneously organizes with an orientational order without developing additional spatial periodic order. In this thesis I show how the effects of this electronic nematic order can be explicitly revealed by observing the response of the system to in-plane uniaxial stress. I present transport measurements of single crystal samples of various iron-based superconductors held under an in-situ tunable strain at temperatures above the phase transition, which explicitly confirm that the structural transition is fundamentally driven by a thermodynamic instability in the electronic part of the free energy. I will also discuss the nematic fluctuations prevailing throughout the overdoped part of the phase diagram, which suggests that a quantum phase transition occurs at the optimal doped composition. Finally, I will describe the in-plane resistivity anisotropy measurements of detwinned samples at temperatures below phase transition, which potentially reveals an intriguing interplay between topological protected Dirac pockets and spin/orbital ordering.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2012 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Chu, Jiun-Haw |
|---|---|
| Associated with | Stanford University, Department of Applied Physics |
| Primary advisor | Fisher, Ian R. (Ian Randal) |
| Thesis advisor | Fisher, Ian R. (Ian Randal) |
| Thesis advisor | Kivelson, Steven |
| Thesis advisor | Shen, Zhi-Xun |
| Advisor | Kivelson, Steven |
| Advisor | Shen, Zhi-Xun |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Jiun-Haw Chu. |
|---|---|
| Note | Submitted to the Department of Applied Physics. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2012. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2012 by Jiun-Haw Chu
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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