Physics Professor and Paul and Suzi Schutt Endowed Chair of Science, Materials Focus Area Team Member; Illinois Institute of Technology Institutional PI, SQMS
Areas of Expertise: Condensed Matter Physics, Materials Science
John Zasadzinski received his Ph.D. in 1980 working at Ames National Laboratory at Iowa State University in the area of superconducting tunneling spectroscopy. This is a powerful probe of the superconducting state that directly reveals the energy gap of the superconductor and the mechanism of pairing. For his Ph.D. thesis, John helped develop a new technique known as Proximity Effect Tunneling Spectroscopy. He continued to use the tunneling method on novel materials such as high temperature superconductors, multiband, and Fe-based superconductors, with much of the work being done in collaboration with scientists at Argonne Lab.
John was fortunate to be elected Fellow of the American Physical Society in 2010 and shortly after received an Endowed Chair Professorship at IIT. His work with SQMS is closely related to his graduate research on superconducting Nb and the compound Nb3Sn. He focuses on a method known as point-contact tunneling, which is similar to a scanning tunneling microscope where only the tip actually touches the surface of the superconductor. This has the additional benefit of giving information on the Nb surface oxide, which is known to be complex and defective and is a likely source of noise in superconducting transmon qubits that incorporate a Nb capacitor. John believes this research will help mitigate the problems of the oxide layer and improve the coherence times of qubits made by Rigetti Computing.