Numerical studies of electron-phonon mediated superconductors
Abstract/Contents
- Abstract
- Electron-phonon interactions are ubiquitous in materials and give rise to bipolarons, charge-density wave order, and superconductivity. The Holstein model is a toy model of electrons coupled to phonons and exhibits much of the same low-energy physics observed in real materials. We study the Holstein model in two dimensions in the limit of weak-coupling through many-body perturbation theory to compute and analyze the superconducting and charge-density wave susceptibilities and various spectral properties. These calculations are performed for systems both in and out of equilibrium and make connections with angle-resolved photoemission and time-resolved angle-resolved photoemission spectroscopy. For systems in equilibrium, we discuss the enhancement of superconductivity driven by the renormalization of the phonon propagator and a surprising difference in two common definitions of the dimensionless electron-phonon coupling strength. Out of equilibrium, we simulate a novel method of determining electron-phonon coupling strength by analyzing electron relaxation dynamics and also characterize the Higgs excitation in a \textit{d}-wave superconductor. In the intermediate coupling limit, no perturbative apporoach or general analytic solution exists for the Holstein model. To overcome this challenge, we study the Holstein model using determinantal quantum Monte Carlo which provides a numerically exact and unbiased method to explore the superconducting and charge-density wave tendencies across a wide range of the phase diagram. We find that superconductivity is optimized at intermediate electron densities and intermediate coupling strength and the strength of the superconducting tendency monotonically increases with phonon frequency.
Description
| Type of resource | text |
|---|---|
| Form | electronic resource; remote; computer; online resource |
| Extent | 1 online resource. |
| Place | California |
| Place | [Stanford, California] |
| Publisher | [Stanford University] |
| Copyright date | 2020; ©2020 |
| Publication date | 2020; 2020 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Author | Nosarzewski, Benjamin Lee |
|---|---|
| Degree supervisor | Devereaux, Thomas Peter, 1964- |
| Thesis advisor | Devereaux, Thomas Peter, 1964- |
| Thesis advisor | Kivelson, Steven |
| Thesis advisor | Shen, Zhi-Xun |
| Degree committee member | Kivelson, Steven |
| Degree committee member | Shen, Zhi-Xun |
| Associated with | Stanford University, Department of Physics |
Subjects
| Genre | Theses |
|---|---|
| Genre | Text |
Bibliographic information
| Statement of responsibility | Benjamin Nosarzewski. |
|---|---|
| Note | Submitted to the Department of Physics. |
| Thesis | Thesis Ph.D. Stanford University 2020. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2020 by Benjamin Lee Nosarzewski
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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