Identifying the origin of lossy defects in Josephson junctions
Abstract
UIUC are currently in the noisy-intermediate-scale (NISQ) era of quantum computing. Chips com- posed of tens of superconducting qubits have been demonstrated, which has served to highlight the importance of full control over the environment of superconducting qubits. An important but uncontrolled component of the superconducting qubit environment are the defects located in the Josephson junctions (JJs) of every superconducting qubit. The effect of these defects is well- known- defects strongly-coupled to the qubit lead to dead zones in frequency where the qubit cannot be measured or used and defects that are weakly-coupled lead to decreased relaxation times. Yet, both the origin of the defects and a recipe for eliminating them remains unknown. UIUC propose to investigate these lossy defects (known as two-level systems or TLS s) using, for the first time, a combination of structural analysis using scanning tunneling electron microscopy, elemental analysis using electron energy loss spectroscopy, microwave loss measurements using flux-tunable resonators and fixed-frequency transmons, and measurement-informed first-principles materials modeling.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 14, 2024
- Source ID
- FA95502310690
Entities
People
- Angela Kouris
Organizations
- Air Force Office of Scientific Research
- United States Air Force
- University of Illinois Urbana–Champaign