Exploring Unique Geometries and Materials in Josephson Junctions for High Coherence Superconducting Qubits 

With respect to potential technologies for performing quantum computation, superconducting qubits represents the most mature platform of technological viability. Nonetheless, despite massive improvements in the performance of these devices, which have largely made possible through advancements in device geometry, material quality continues to curb performance and requires a more detailed understanding. As the impurities in the materials inherent to these devices as well as the surfaces and interfaces serve as sources of microwave loss, we take a materials-oriented approach to systematically improve the quality of each of the constituent sub-systems in order to make demonstrable enhancements in coherence times. In this talk, we discuss the fabrication of multilayer Josephson junction architectures. Through a detailed investigation combining device fabrication with materials characterization and measurements, we identify an optimal set of deposition and etching parameters for reproducibly preparing these multilayer architectures and discuss our learnings to date.