Physical Sciences and Mathematics Commons^™

Quantum Field Theories, Topological Materials, And Topological Quantum Computing, Muhammad Ilyas

Dissertations and Theses

A quantum computer can perform exponentially faster than its classical counterpart. It works on the principle of superposition. But due to the decoherence effect, the superposition of a quantum state gets destroyed by the interaction with the environment. It is a real challenge to completely isolate a quantum system to make it free of decoherence. This problem can be circumvented by the use of topological quantum phases of matter. These phases have quasiparticles excitations called anyons. The anyons are charge-flux composites and show exotic fractional statistics. When the order of exchange matters, then the anyons are called non-Abelian anyons. Majorana …

Developing Effective Theories: A Case Study In Monolayer Iron Selenide, Joseph O'Halloran

Theses and Dissertations

In this work, we outline the development of a series of models which have allowed us to investigate the low-temperature phases of monolayer FeSe. These models are built using group theoretic arguments to ensure the constraints provided by the crystal symmetry are satisfied. We investigate the interplay between stripe antiferromagnetism and spin-vortex crystal order in the framework of the Landau theory of phase transitions. By considering inversion symmetry breaking terms in the Landau free-energy, we show that the spin-vortex crystal is preferred when the non-symmorphic parent symmetry group $P4/nmm$ is reduced to a symmorphic subgroup.

We also consider symmetry constraints …

Majorana Quasiparticles In Topological Material Interfaces, David Alspaugh

LSU Doctoral Dissertations

In this dissertation we analyze how Majorana quasiparticles found on material interfaces of both topological insulators (TIs) and topological superconductors (TSCs) are affected by imperfections within their local environment. While these quasiparticles are predicted to be critical for the construction of quantum computers, they are typically modeled only under pristine conditions. Thus, although quantum computers may require the spatial manipulation of Majorana quasiparticles, these topological material interfaces are commonly studied in static contexts and their response to manipulation remains an open question. We first demonstrate that interface potentials on the topological insulator Bi₂Se₃ can enable the emergence …

Magnetism In Curved Geometries, R. Streubel, E. Y. Tsymbal, P. Fischer

Evgeny Tsymbal Publications

No abstract provided.

Dimentia: Footnotes Of Time, Zachary Hait

Senior Projects Spring 2021

Time from the physicist's perspective is not inclusive of our lived experience of time; time from the philosopher's perspective is not mathematically engaged, in fact Henri Bergson asserted explicitly that time could not be mathematically engaged whatsoever. What follows is a mathematical engagement of time that is inclusive of our lived experiences, requiring the tools of storytelling.

Combining Cryo-Em Density Map And Residue Contact For Protein Secondary Structure Topologies, Maytha Alshammari, Jing He

Computer Science Faculty Publications

Although atomic structures have been determined directly from cryo-EM density maps with high resolutions, current structure determination methods for medium resolution (5 to 10 Å) cryo-EM maps are limited by the availability of structure templates. Secondary structure traces are lines detected from a cryo-EM density map for α-helices and β-strands of a protein. A topology of secondary structures defines the mapping between a set of sequence segments and a set of traces of secondary structures in three-dimensional space. In order to enhance accuracy in ranking secondary structure topologies, we explored a method that combines three sources of information: a set …