Work

Interplay of coupling, residual, and quasiparticle losses for the frequency- and temperature-dependent quality factor of superconducting resonators

Year: 2025

Type: article

Abstract: The overall, loaded quality factor Q L quantifies the loss of energy stored in a resonator. Here we discuss on general grounds how Q L of a planar microwave resonator made of a conventional superconductor should depend on temperature and frequency. We consider contributions to Q L due to dissipation by thermal quasiparticles ( Q QP ), due to residual dissipation ( Q Res ), and due to coupling ( Q C ). We present experimental data obtained with superconducting stripline resonators fabricated from lead (Pb), with different center conductor widths and different coupling gaps. We probe the resonators at various harmonics between 0.7 GHz and 6 GHz and at temperatures between 1.5 K and 7 K. We find a strongly frequency- and temperature-dependent Q L , which we can describe by a lumped-element model. For certain resonators at lowest temperatures we observe a maximum in the frequency-dependent Q L when Q Res and Q C match, and here the measured Q L can exceed 2 × 10 5 .

Source: Superconductor Science and Technology

DOI: 10.1088/1361-6668/adcc5f

Authors: Elies Ben Achour, Cenk Beydeda, Gabriele Untereiner, Martin Dressel, Marc Scheffler

Institution: University of Stuttgart

Language: English

Topic: Superconducting and THz Device Technology

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $3,325

Funder: Bundesministerium für Bildung und Forschung