Symmetry Breaking, Order-by-Disorder, Fragmentation, and Spin-Liquids in the Magnetic Pyrochlore Lattice with Anisotropic Interactions
| dc.contributor.author | Lozano Gomez, Daniel | |
| dc.date.accessioned | 2023-01-26T21:19:33Z | |
| dc.date.issued | 2023-01-26 | |
| dc.date.submitted | 2023-01-26 | |
| dc.description.abstract | Within the study of frustrated magnetism, the pyrochlore lattice is deemed a fruitful ground where phenomena such as quantum and thermal order-by-disorder, moment fragmentation, and spin-liquids, both quantum and classical, might be realized. In this thesis, we study a Heisenberg and Dzyaloshisnkii-Moriya nearest-neighbor Hamiltonian in this lattice which presents all the above phenomena, providing a quantitative description through the application of both analytical and numerical approaches. First, we obtain a phase diagram where three long-range ordered phases (two antiferromagnetic and one ferromagnetic), and two spin-liquid points, the well-known classical Coulomb phase and a new spin-liquid, that we dub “order-by-disorder selected spin liquid”, are identified. We then proceed to study the order-by-disorder selection in two of the long-range ordered phases (an antiferromagnetic and a ferromagnetic phase) and show that the quantum order-by-disorder selection mechanism in one of these phases is only produced at non-zero temperature, i.e. without zero-temperature quantum order-by-disorder. Then, we study the newly identified spin-liquid and the evolution of its correlation function as a function of temperature. The correlation function of this spin-liquid presents pinch-lines, twofold and fourfold pinch-points at high temperature, whereas at low temperature, these features are replaced by a spin-ice pattern. This effect is a consequence of the order-by-disorder selection of an extensive subset of ground-states (the spin-ice states) within the manifold. Finally, we study the phenomenon of fragmentation, commonly referred to as the observation of both sharp pinch-points and Bragg peaks in the correlation functions of an ordered phase. Specifically, we demonstrate how this effect is a consequence of a Helmholtz-Hodge decomposition of the spin mode excitations in an ordered phase, and is therefore expected to be observed especially for Hamiltonians whose interaction parameters are proximate to a spin-liquid point. | en |
| dc.identifier.uri | http://hdl.handle.net/10012/19133 | |
| dc.language.iso | en | en |
| dc.pending | false | |
| dc.publisher | University of Waterloo | en |
| dc.relation.uri | https://github.com/daniel-lozano/Thesis_animations | en |
| dc.subject | frustrated magnetism | en |
| dc.subject | order by disorder | en |
| dc.subject | spin liquid | en |
| dc.subject | pyrochlore lattice | en |
| dc.title | Symmetry Breaking, Order-by-Disorder, Fragmentation, and Spin-Liquids in the Magnetic Pyrochlore Lattice with Anisotropic Interactions | en |
| dc.type | Doctoral Thesis | en |
| uws-etd.degree | Doctor of Philosophy | en |
| uws-etd.degree.department | Physics and Astronomy | en |
| uws-etd.degree.discipline | Physics | en |
| uws-etd.degree.grantor | University of Waterloo | en |
| uws-etd.embargo | 2025-01-25T21:19:33Z | |
| uws-etd.embargo.terms | 2 years | en |
| uws.contributor.advisor | Gingras, Michel | |
| uws.contributor.affiliation1 | Faculty of Science | en |
| uws.peerReviewStatus | Unreviewed | en |
| uws.published.city | Waterloo | en |
| uws.published.country | Canada | en |
| uws.published.province | Ontario | en |
| uws.scholarLevel | Graduate | en |
| uws.typeOfResource | Text | en |
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