Date of Award
5-2024
Document Type
Thesis
Degree Name
Master of Science (MS)
Department
Physics
Committee Chair/Advisor
Kasra Sardashti
Committee Member
Chad Sosolik
Committee Member
Joan Marler
Abstract
Superconducting qubits have emerged as a promising platform for realizing error-corrected quantum computing. Reaching the minimum threshold for error correction requires scaling the number of qubits well beyond the current numbers while improving their coherence and minimizing their crosstalk. Such daunting demands require groundbreaking innovations in the design of superconducting quantum circuits as well as in engineering the materials integrated into the devices. This thesis explores materials solutions for two different scalability problems: 1) crosstalk and 2) loss due to surface oxidation. The crosstalk is addressed by making voltage-tunable superconductor-semiconductor Josephson junctions (JJs). For the loss due to surface oxidation, we explore ruthenium (Ru) as a capping layer that can inhibit surface oxidation rates for the underlying niobium (Nb) or tantalum (Ta) thin films. The thesis starts with an introduction to superconductivity and how it led to superconducting quantum bits. Chapter 2 discusses the experimental tools utilized for the fabrication and characterization of thin films and devices. Chapter 3 focuses on Nb/Ge interfaces for hybrid superconductor-semiconductor devices. In Chapter 4 we discuss Ru thin films as a capping layer for superconducting quantum circuits. We analyze the oxide formation on Ru thin film surfaces and characterize the electronic transport properties. The thesis concludes with the future direction for the two parts of this study including integration of our chemically-abrupt Nb/Ge interfaces into voltage-tunable JJs and the application of our thin-film superconducting Ru capping layers as passivation layers in superconducting resonators.
Recommended Citation
Langa Junior, Bernardo Jaime, "Studying Superconducting Thin Films for Quantum Computing Applications" (2024). All Theses. 4223.
https://tigerprints.clemson.edu/all_theses/4223