Stability of superconducting resonators: Motional narrowing and the role of Landau-Zener driving of two-level defects.

ABSTRACT: Frequency instability of superconducting resonators and qubits leads to dephasing and time-varying energy loss and hinders quantum processor tune-up. Its main source is dielectric noise originating in surface oxides. Thorough noise studies are needed to develop a comprehensive understanding and mitigation strategy of these fluctuations. We use a frequency-locked loop to track the resonant frequency jitter of three different resonator types—one niobium nitride superinductor, one aluminum coplanar waveguide, and one aluminum cavity—and we observe notably similar random telegraph signal fluctuations. At low microwave drive power, the resonators exhibit multiple, unstable frequency positions, which, for increasing power, coalesce into one frequency due to motional narrowing caused by sympathet

SUBMITTER: Niepce D 

PROVIDER: S-EPMC8462906 | biostudies-literature | 2021 Sep

REPOSITORIES: biostudies-literature