Modelling of Berry phase and Fermi-level topologies for emergent quantum phenomena prediction in selected solid state systems
| dc.contributor.advisor | Salagaram, Trisha | |
| dc.contributor.advisor | Ukpong, Magnus | |
| dc.contributor.author | Tematio, Gaël-Pacôme Nguimeya | |
| dc.date.accessioned | 2026-01-13T06:59:53Z | |
| dc.date.available | 2026-01-13T06:59:53Z | |
| dc.date.issued | 2025 | |
| dc.date.updated | 2026-01-13T06:57:19Z | |
| dc.description.abstract | Topological materials host electronic states that remain robust against perturbations and offer routes to novel quantum functions. This thesis investigates three representative compounds - SrSi2, CoSi, and NbP - to reveal how external stimuli, namely tensile strain and electric fields, tune their electronic bands and topological traits. By combining first-principles calculations with model Hamiltonian experiments, we aim to uncover mechanisms behind quantum phase transitions (QPTs) and to establish design principles for materials with tailored quantum states. We perform density functional theory (DFT) calculations within the plane-wave pseudopotential framework using the Quantum ESPRESSO (QE) suite. Spin-orbit coupling (SOC) is included to capture relativistic effects critical for topological properties. We generate maximally localized Wannier functions (MLWFs) with Wannier90 and construct tight-binding (TB) models to compute Berry curvature, surface state spectra, and Fermi arc patterns via WannierTools. To probe QPTs in SrSi2, we employ the Quantum Lattice environment to simulate a renormalized graphene lattice, mapping analogies between external perturbations and topological responses in both systems. | |
| dc.identifier.apacitation | Tematio, G. N. (2025). <i>Modelling of Berry phase and Fermi-level topologies for emergent quantum phenomena prediction in selected solid state systems</i>. (). University of Cape Town ,Faculty of Science ,Department of Physics. Retrieved from http://hdl.handle.net/11427/42534 | en_ZA |
| dc.identifier.chicagocitation | Tematio, Gaël-Pacôme Nguimeya. <i>"Modelling of Berry phase and Fermi-level topologies for emergent quantum phenomena prediction in selected solid state systems."</i> ., University of Cape Town ,Faculty of Science ,Department of Physics, 2025. http://hdl.handle.net/11427/42534 | en_ZA |
| dc.identifier.citation | Tematio, G.N. 2025. Modelling of Berry phase and Fermi-level topologies for emergent quantum phenomena prediction in selected solid state systems. . University of Cape Town ,Faculty of Science ,Department of Physics. http://hdl.handle.net/11427/42534 | en_ZA |
| dc.identifier.ris | TY - Thesis / Dissertation AU - Tematio, Gaël-Pacôme Nguimeya AB - Topological materials host electronic states that remain robust against perturbations and offer routes to novel quantum functions. This thesis investigates three representative compounds - SrSi2, CoSi, and NbP - to reveal how external stimuli, namely tensile strain and electric fields, tune their electronic bands and topological traits. By combining first-principles calculations with model Hamiltonian experiments, we aim to uncover mechanisms behind quantum phase transitions (QPTs) and to establish design principles for materials with tailored quantum states. We perform density functional theory (DFT) calculations within the plane-wave pseudopotential framework using the Quantum ESPRESSO (QE) suite. Spin-orbit coupling (SOC) is included to capture relativistic effects critical for topological properties. We generate maximally localized Wannier functions (MLWFs) with Wannier90 and construct tight-binding (TB) models to compute Berry curvature, surface state spectra, and Fermi arc patterns via WannierTools. To probe QPTs in SrSi2, we employ the Quantum Lattice environment to simulate a renormalized graphene lattice, mapping analogies between external perturbations and topological responses in both systems. DA - 2025 DB - OpenUCT DP - University of Cape Town KW - Topological materials KW - Quantum ESPRESSO LK - https://open.uct.ac.za PB - University of Cape Town PY - 2025 T1 - Modelling of Berry phase and Fermi-level topologies for emergent quantum phenomena prediction in selected solid state systems TI - Modelling of Berry phase and Fermi-level topologies for emergent quantum phenomena prediction in selected solid state systems UR - http://hdl.handle.net/11427/42534 ER - | en_ZA |
| dc.identifier.uri | http://hdl.handle.net/11427/42534 | |
| dc.identifier.vancouvercitation | Tematio GN. Modelling of Berry phase and Fermi-level topologies for emergent quantum phenomena prediction in selected solid state systems. []. University of Cape Town ,Faculty of Science ,Department of Physics, 2025 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/42534 | en_ZA |
| dc.language.iso | en | |
| dc.language.rfc3066 | eng | |
| dc.publisher.department | Department of Physics | |
| dc.publisher.faculty | Faculty of Science | |
| dc.publisher.institution | University of Cape Town | |
| dc.subject | Topological materials | |
| dc.subject | Quantum ESPRESSO | |
| dc.title | Modelling of Berry phase and Fermi-level topologies for emergent quantum phenomena prediction in selected solid state systems | |
| dc.type | Thesis / Dissertation | |
| dc.type.qualificationlevel | Doctoral | |
| dc.type.qualificationlevel | PhD |