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Bayesian Inference and Collapse Models in Levitated Optomechanics / SHAUN LAING
Swansea University Author: SHAUN LAING
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Copyright: The Author, Shaun J. Laing, 2024 CC BY - Distributed under the terms of a Creative Commons Attribution 4.0 License (CC BY 4.0).
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DOI (Published version): 10.23889/SUThesis.66884
Abstract
An apparent contradiction exists between the wave nature of quantum mechanics allowing for superposition of states, and the observations of classical mechanics.Several possible solutions for this discrepancy have been suggested including the proposal that quantum and classical dynamics are simply ap...
| Published: |
Swansea University, Wales, UK
2024
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| Institution: | Swansea University |
| Degree level: | Doctoral |
| Degree name: | Ph.D |
| Supervisor: | Bateman, J., E., & O'Keeffe, K. |
| URI: | https://cronfa.swan.ac.uk/Record/cronfa66884 |
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| Abstract: |
An apparent contradiction exists between the wave nature of quantum mechanics allowing for superposition of states, and the observations of classical mechanics.Several possible solutions for this discrepancy have been suggested including the proposal that quantum and classical dynamics are simply approximations to a universal dynamics. Collapse models modify the usual Schrödinger equation that provides this universal dynamics and can be tested experimentally. In this thesis, we conceive of a Talbot matter-wave interferometer to probe the superposition of high-mass nanoparticles. We extend existing descriptions beyond the point-like regime allowing us to test collapse models with masses up to 109u. During this development, we discover and correct an error in calculating the Talbot coefficients for a laser grating in the Mie regime. A Bayesian analysis is performed on simulated data making greater use of each recorded arrival position of the nanoparticle and provide a real-valued probability density to the parameter space as opposed to the binary exclusion plots of previous works. We find a limit to the size of spherical particles that can be used as a result of the grating transformation being averaged over the particle. As a result, during a collaboration with the Geraci group at Northwestern University, we develop a numerical method for finding where arbitrarily shaped particles scatter information about their position and use these techniques to derive the Talbot coefficients for arbitrary particle geometries. |
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| Item Description: |
A selection of content is redacted or is partially redacted from this thesis to protect sensitive and personal information |
| Keywords: |
Physics, Quantum Physics, Optomechanics, Talbot Effect, Collapse Models, Matter Wave Interferometry |
| College: |
Faculty of Science and Engineering |
| Funders: |
EPSRC doctoral training grant |