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Scanning Tunneling Microscopy Studies Of Superconducting Single Layer Iron Selenide On Strontium Titanate, Zhuozhi Ge

Theses and Dissertations

The search for high temperature superconductivity has been a prominent topic in the field of condensed matter physics ever since the discovery of this novel phenomenon more than 100 years ago. In addition to the search for new materials, interfacial superconductivity has shown great potential as demonstrated recently in monolayer FeSe grown on SrTiO3 (STO) (001) substrate, where superconducting transition temperature (Tc) has been enhanced by more than an order of magnitude compared to the bulk value. The uniqueness of this approach is the direct placement of the superconducting layer on a secondary substrate, which facilitates the independent control of …

Internal And External Harmonic Functions In Flat-Ring Coordinates, Lijuan Bi

Theses and Dissertations

The goal of this dissertation is to derive expansions for a fundamental solution of Laplace's equation in flat-ring coordinates in three-dimensional Euclidean space. These expansions are in terms of harmonic functions in the interior and the exterior of two different types of regions, "flat rings" and "peanuts" according to their shapes. We solve Laplace's equation in the interior and the exterior of these regions using the method of separation of variables. The internal and external "flat-ring" and "peanut" harmonic functions are expressed in terms of Lamé functions.

Neutron Star Tidal Deformability And Gravitational Self-Force, Eric Van Oeveren

Theses and Dissertations

The recent direct observations of gravitational waves by the LIGO-Virgo collaboration [1-6] have been important pieces of evidence in agreement with Einstein's theory of gravity, the General Theory of Relativity. In addition, they open an era of gravitational wave astronomy that promises to give us much more information on the systems that produce gravitational radiation. Perhaps most prominent among these are binary systems composed of either two black holes, two neutron stars, or one black hole and one neutron star. This dissertation details theoretical predictions regarding such systems.

It is hoped that gravitational radiation emanating from binary systems that include …

Crystal Growth And Manipulation Of Intercalated Chalcogenides As Superconductors And Topological Insulators, Nathaniel Smith

Theses and Dissertations

Superconductors are unusual quantum materials which offer no resistance to electric current. The fascinating physics of this phenomenon is complemented by wide-ranging technical applications from power transmission to magnetic levitation. Commercially successful superconductors are found in powerful magnets in medical imaging, particle accelerators, and next-generation quantum computing. In my effort to uncover the mysteries and fundamental mechanisms of superconductivity, I use an array of techniques to synthesize and study single crystals of unconventional superconductors including the iron telluride and bismuth selenide family of superconductors. My study of atomic valence and crystal structure in iron telluride has uncovered previously unknown chemical …

Time-Resolved Structural Enzymology At X-Ray Free Electron Lasers, Tyler Norwood

Theses and Dissertations

Within the last decade, X-ray Free Electron Lasers (XFELs) have emerged across the world. These XFELs produce X-ray pulses with a duration on the order of femtoseconds, each of which contains 1012 photons. Before the XFEL, the brightest X-ray sources were 3rd generation synchrotrons. While these facilities are still very important for many experiments, XFELs allow for time-resolved experiments with femtosecond time resolution and mixing experiments that are not possible at the synchrotron. Enzymatic processes have promising prospects for medicine which use proteins as drug targets and enhance our understanding of these important biomolecules.

A number of procedures are involved …

Studies In Gravitational-Wave Astronomy And Tests Of General Relativity, Hong Qi

Theses and Dissertations

Modern astronomical data sets provide the opportunity to test our physical theories of the Universe at unprecedented levels of accuracy. This dissertation examines approaches to testing gravitational theories using a) observations of stars orbiting the center of the Milky Way; b) observations of the pulsations of Cepheid variable stars in dwarf galaxies; and c) gravitational-wave observations of compact binary mergers.

Observations of stars orbiting the center of the Milky Way have been used to infer the mass of the putative black hole that exists there. I discuss how well present and future measurements of stellar orbits can constrain the black …

Search For Compact Object Coalescences And Understanding Their Significance Using Data From Advanced Ligo, Debnandini Mukherjee

Theses and Dissertations

Gravitational waves were observed for the first time on September 14, 2015. A 36 and a 29 solar mass black holes were seen to inspiral around each other and merge about 410 Mpc away. This gave momentum to the areas of gravitational wave astrophysics and astronomy. While the universe could be perceived in the electromagnetic spectrum so far, enabling us to "see" it with telescopes, it could now be "listened to" using gravitational waves. Also, black holes being optically dark, could be observed directly for the very first time after this discovery. The 100 year old theory of General Relativity …