Imaging nematic domains in Barium iron arsenide using a scanning quantum cryogenic atom microscope
Abstract/Contents
- Abstract
- The SQCRAMscope is a novel scanning quantum cryogenic atom microscope with a wide scan range and superior magnetic field sensing capabilities. The ultracold-atom-based probe is also sensitive to local electric field and Casimir-Polder potential, making it a versatile multimodal sensor for exploring solid state physics in the mesoscopic regime. In addition, the SQCRAMscope permits easy optical access to the sample, allowing optical excitation and characterization to be tightly integrated with the scanning probe. In this thesis, I will introduce the SQCRAMscope and discuss our efforts in characterizing its scanning capabilities. I will then demonstrate its first use on measuring the spontaneous resistivity anisotropy in the nematic phase of an iron pnictide superconductor. The resistivity anisotropy is often regarded as a proxy of the nematic order parameter, which is critical to the understanding of pairing mechanism in iron-based superconductors. In the nematic phase of BaFe2As2, the formation of twin domains complicates transport measurements of resistivity anisotropy, and often requires the application of an external strain to detwin the crystal. I will show optical polarimetry measurements concurrent with magnetometry on an unstrained crystal that allows identification of magnetic signal with optically-visible twin domains. I will then show that such a spatially-resolved magnetic field measurement is sufficient to extract the spontaneous resistivity anisotropy. We found that the measured resistivity anisotropy is generally smaller than that of the previously reported detwinned bulk crystals, but still within the range of typical sample-to-sample variation.
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 | 2021; ©2021 |
| Publication date | 2021; 2021 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Author | Yang, Fan |
|---|---|
| Degree supervisor | Lev, Benjamin L |
| Thesis advisor | Lev, Benjamin L |
| Thesis advisor | Feldman, Ben |
| Thesis advisor | Fisher, Ian R. (Ian Randal) |
| Degree committee member | Feldman, Ben |
| Degree committee member | Fisher, Ian R. (Ian Randal) |
| Associated with | Stanford University, Department of Applied Physics |
Subjects
| Genre | Theses |
|---|---|
| Genre | Text |
Bibliographic information
| Statement of responsibility | Fan Yang. |
|---|---|
| Note | Submitted to the Department of Applied Physics. |
| Thesis | Thesis Ph.D. Stanford University 2021. |
| Location | https://purl.stanford.edu/ny166mx1858 |
Access conditions
- Copyright
- © 2021 by Fan Yang
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