Improving scanning SQUID techniques through numerical simulations, electronics optimization, and noise reduction
Abstract/Contents
- Abstract
- Scanning SQUID microscopy (SSM) is a powerful tool used to study condensed matter systems with high levels of magnetic field precision at the micron scale. My thesis discusses both the measurement capabilities and theoretical understanding of SSM through numerical simulations and room-temperature electronics development. The first part of the thesis discusses simulations of SSM measurement response. I first present a thorough analysis of the measurement capabilities of my Physics 108 project, in which I and others built a coarse scanning SQUID magnetometer in an attempt to observe superconducting phenomena in YBCO, a copper oxide based high temperature superconductor. Next, I model the measurement response of SQUIDs from the Moler lab and the impact of the pitch angle between the SQUID and sample on magnetometry and susceptometry measurements. In the second part of my thesis, I discuss noise reduction techniques for room-temperature electronics used for the Moler group's scanning SQUID experiments. Two advancements are presented: (1) A PCB-based breakout box with dedicated grounding switches, designed to minimize noise and optimize shielding. (2) A low-noise voltage adder which enables lock-in amplifier measurements with a superimposed dc excitation, such as magnetic susceptibility and transport measurements.
Description
| Type of resource | text |
|---|---|
| Publication date | May 21, 2024; May 21, 2024 |
Creators/Contributors
| Author | Loh, Megan |
https://orcid.org/0000-0002-9754-0868
(unverified)
|
|---|---|---|
| Thesis advisor | Moler, Kathryn | |
| Thesis advisor | Tompkins, Lauren | |
| Degree granting institution | Stanford University | |
| Department | Department of Physics |
Subjects
| Subject | Superconducting quantum interference devices |
|---|---|
| Genre | Text |
| Genre | Thesis |
Bibliographic information
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- License
- This work is licensed under a Creative Commons Attribution Non Commercial 4.0 International license (CC BY-NC).
Preferred citation
- Preferred citation
- Loh, M. (2024). Improving scanning SQUID techniques through numerical simulations, electronics optimization, and noise reduction. Stanford Digital Repository. Available at https://purl.stanford.edu/bf094rb4252. https://doi.org/10.25740/bf094rb4252.
Collection
Undergraduate Theses, Department of Physics
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- Contact
- meganloh@stanford.edu
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