Terahertz near-field imaging of sidewall-induced losses in superconducting qubits
Abstract
Correlating superconducting qubit performance with advanced materials analysis is a key strategy for improving coherence. Existing diagnostics for key properties, such as dielectric loss, structural discontinuity, and interface heterogeneity, often rely on destructive electron microscopy or low-throughput millikelvin measurements. Here, we demonstrate noninvasive terahertz (THz) nano-imaging/spectroscopy of encapsulated niobium transmon qubits as a high-throughput proxy for performance evaluation. We identify large variations in sidewall near-field signals, implicating sidewall loss and discontinuity as major coherence limiters, and also use THz hyperspectral line scans to probe dielectric responses and field participation at Al junction interfaces.
Article Details
Journal Info
Applied Physics Letters
American Institute of Physics
Authors (19)
Richard H. J. Kim
Ames National Laboratory, US Department of Energy 1 , Ames, Iowa 50011,
Samuel J. Haeuser
Department of Physics and Astronomy, Iowa State University 2 , Ames, Iowa 50011,
Joong-Mok Park
Ames National Laboratory, US Department of Energy 1 , Ames, Iowa 50011,
Randall K. Chan
Department of Physics and Astronomy, Iowa State University 2 , Ames, Iowa 50011,
Jin-Su Oh
Ames National Laboratory, US Department of Energy 1 , Ames, Iowa 50011,
Thomas Koschny
Ames National Laboratory, US Department of Energy 1 , Ames, Iowa 50011,
Lin Zhou
Matthew J. Kramer
Ames National Laboratory, US Department of Energy 1 , Ames, Iowa 50011,
Akshay A. Murthy
Superconducting Quantum Materials and Systems Division, Fermi National Accelerator Laboratory (FNAL) 3 , Batavia, Illinois 60510,
Mustafa Bal
Superconducting Quantum Materials and Systems Division, Fermi National Accelerator Laboratory (FNAL) 3 , Batavia, Illinois 60510,
Francesco Crisa
Superconducting Quantum Materials and Systems Division, Fermi National Accelerator Laboratory (FNAL) 3 , Batavia, Illinois 60510,
Sabrina Garattoni
Superconducting Quantum Materials and Systems Division, Fermi National Accelerator Laboratory (FNAL) 3 , Batavia, Illinois 60510,
Shaojiang Zhu
Superconducting Quantum Materials and Systems Division, Fermi National Accelerator Laboratory (FNAL) 3 , Batavia, Illinois 60510,
Andrei Lunin
Superconducting Quantum Materials and Systems Division, Fermi National Accelerator Laboratory (FNAL) 3 , Batavia, Illinois 60510,
David Olaya
National Institute of Standards and Technology 4 , Boulder, Colorado 80305,
Peter Hopkins
National Institute of Standards and Technology 4 , Boulder, Colorado 80305,
Alex Romanenko
Superconducting Quantum Materials and Systems Division, Fermi National Accelerator Laboratory (FNAL) 3 , Batavia, Illinois 60510,
Anna Grassellino
Superconducting Quantum Materials and Systems Division, Fermi National Accelerator Laboratory (FNAL) 3 , Batavia, Illinois 60510,
Jigang Wang
Artemisinin Research Center and Institute of Chinese Materia Medica