- Library Home /
- Search Collections /
- Open Collections /
- Browse Collections /
- UBC Theses and Dissertations /
- Scanning tunneling microscopy study of superconducting...
Open Collections
UBC Theses and Dissertations
UBC Theses and Dissertations
Scanning tunneling microscopy study of superconducting pairing symmetry : application to LiFeAs Chi, Shun
Abstract
Identifying the pairing symmetry is a crucial step towards uncovering the superconducting mechanism. The pairing symmetry and interactions leading to pairing in the iron-based high-temperature superconductors are under debate. In this thesis work, the pairing symmetry of LiFeAs, a stoichiometric superconductor in the iron-based family, is studied by scanning tunneling microscopy. The tunneling conductance spectrum in a defect-free region shows two nodeless superconducting gaps. In addition, a dip-hump above-gap structure was observed, indicating coupling between the superconducting carriers and bosonic modes. Defect bound states were measured for iron-site defects. The bound states are pinned to the gap edge of the small superconducting gap, consistent with theoretical predictions for a sign-changing pairing symmetry. Finally, the observed Bogoliubov quasiparticle interference associated with scattering from defects provides compelling evidence for an s+- pairing symmetry in LiFeAs.
Item Metadata
Title |
Scanning tunneling microscopy study of superconducting pairing symmetry : application to LiFeAs
|
Creator | |
Publisher |
University of British Columbia
|
Date Issued |
2014
|
Description |
Identifying the pairing symmetry is a crucial step towards uncovering the superconducting mechanism. The pairing symmetry and interactions leading to pairing in the iron-based high-temperature superconductors are under debate. In this thesis work, the pairing symmetry of LiFeAs, a stoichiometric superconductor in the iron-based family, is studied by scanning tunneling microscopy. The tunneling conductance spectrum in a defect-free region shows two nodeless superconducting gaps. In addition, a dip-hump above-gap structure was observed, indicating coupling between the superconducting carriers and bosonic modes. Defect bound states were measured for iron-site defects. The bound states are pinned to the gap edge of the small superconducting gap, consistent with theoretical predictions for a sign-changing pairing symmetry. Finally, the observed Bogoliubov quasiparticle interference associated with scattering from defects provides compelling evidence for an s+- pairing symmetry in LiFeAs.
|
Genre | |
Type | |
Language |
eng
|
Date Available |
2014-10-06
|
Provider |
Vancouver : University of British Columbia Library
|
Rights |
Attribution-NonCommercial-NoDerivs 2.5 Canada
|
DOI |
10.14288/1.0166065
|
URI | |
Degree | |
Program | |
Affiliation | |
Degree Grantor |
University of British Columbia
|
Graduation Date |
2014-11
|
Campus | |
Scholarly Level |
Graduate
|
Rights URI | |
Aggregated Source Repository |
DSpace
|
Item Media
Item Citations and Data
Rights
Attribution-NonCommercial-NoDerivs 2.5 Canada
Admin Actions
You are logged in as an administrator and have access to the following item actions:
Re-ingest ItemNote: Re-ingesting will take roughly 5 minutes per item.
Clear Item Cache