ExpandQISE: Track 2: URI-PQI Collaboration - Application Of Quantum Fundamentals To Advance Research and Workforce Development

Non-technical Abstract: Quantum computing is making rapid progress toward the goal of a fault tolerant computer. This advance can be attributed to the breakthroughs in gate fidelities and coherence times, placing quantum computation on the threshold of practicality. However, all qubits are subject to loss of information and remediating that loss is the key to advancing this goal, where the error correction threshold has been exceeded, environmental effects have been mitigated, and errors do not spread. Moreover, the supply of a skilled quantum workforce is falling behind demand, and projections suggest that this deficit needs tobe addressed. The University of Rhode Island (URI) and the Pittsburgh Quantum Institute (a collaboration among University of Pittsburgh, Carnegie Mellon University and Duquesne University) are collaborating to improve the robustness of qubits, while also addressing the need for quantum workforce development. Technical Abstract: A current leading contender for quantum computing is the superconducting qubit. “Parasitic” two-level-system (TLS) defects, which limit coherence times of superconducting qubits, are among the main hurdles in the quest for fault tolerance. A fuller understanding of the mechanisms that couple the TLS to the qubit and the resulting coupling of TLS to the environment could result in a mitigation of the decoherence. There is also significant knowledge to be gained from the understanding of TLS in amorphous materials. The methodology behind this research is to vary the growth parameters of key constituent elements of the state-of-the-art superconducting qubits, such as transmons and fluxoniums. The newly built superconductor deposition tool at the Petersen Institute for Nanoscience and Engineering is a 3-chamber high vacuum thin film deposition system which includes surface analysis tools, in a unique setup. The chamber allows for high-temperature sputter deposition of superconducting layers of NbN, NbTiN and Ta, which are used a base layers for microwave resonators, transmon pads and ground planes. Most of the work on the characterization of TLS and loss mechanisms does not require full qubit measurements but can be performed through a combination of surface science and microwave characterization techniques. In the later stages of the project, optimized thin superconducting layers, substrates, and capping layers are used as the basis for qubit devices, where direct comparison of coherence times can be performed. Through this grant the institutions are creating programs that make major scientific advancements, enhance research and curricular reform at all collaborating institutions, and incentivize students to pursue studies in quantum information science and engineering. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.