Thesis Title: Theory of Superconducting Quantum Devices and Reconfigurable Quantum Materials for Quantum Computing Applications

Abstract: Quantum computing is a quickly growing field, and superconducting platforms show promise in development toward scalable quantum computing systems. A major limitation on quantum computing systems is scaling, as it proves difficult to build quantum computers which operate on many qubits and preserve quantum information. Surmounting these issues requires developing new quantum hardware with a deep understanding of the properties of quantum devices in mind. In this Dissertation, I theoretically investigate the properties of quantum hardware and how they can be used to design new devices for quantum computing applications. I will describe my work on examining fundamental properties of reconfigurable materials which may prove useful in these applications, in particular by modeling and engineering the band structure of graphene with an electrostatic potential and by modeling supercurrents in 2D superconductors at complex oxide heterointerfaces. Then I will describe designing super- conducting hardware which relies on the nonlinearity of Josephson junctions, specifically amplifiers and masers. These devices each represent a significant new property or improvement in performance along some dimension as compared to the quantum hardware of the past, and the further investigation of these properties in this Dissertation lays the groundwork for building useful, practical devices for quantum computing.