Document Type
Article
Publication Date
2014
DOI
10.1063/1.4867339
Publication Title
Applied Physics Letters
Volume
104
Issue
9
Pages
092601
Abstract
Measurements of the quality factor, Q, of Nb superconducting microwave resonators often show that Q increases by ≃10%–30% with increasing radio-frequency (rf) field, H, up to ∼15–20 mT. Recent high temperature heat treatments can amplify this rf field-induced increase of Q up to ≃50%–100% and extend it to much higher fields ≃100 mT, but the mechanisms of the enhancement of Q(H) remain unclear. Here, we suggest a method to reveal these mechanisms by measuring temperature dependencies of Q at different rf field amplitudes. We show that the increase of Q(H) does not come from a field dependent quasi-particles activation energy or residual resistance, but rather results from the smearing of the density of state by the rf field.
Rights
© 2014 the authors and AIP publishing
This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in
Ciovati, G., Dhakal, P., & Gurevich, A. (2014). Decrease of the surface resistance in superconducting niobium resonator cavities by the microwave field. Applied Physics Letters, 104(9), 092601.
and may be found at https://doi.org/10.1063/1.4867339
Original Publication Citation
Ciovati, G., Dhakal, P., & Gurevich, A. (2014). Decrease of the surface resistance in superconducting niobium resonator cavities by the microwave field. Applied Physics Letters, 104(9), 092601. https://doi.org/10.1063/1.4867339
ORCID
0000-0003-0759-8941 (Gurevich)
Repository Citation
Ciovati, G.; Dhakal, P.; and Gurevich, A., "Decrease of the Surface Resistance in Superconducting Niobium Resonator Cavities by the Microwave Field" (2014). Physics Faculty Publications. 900.
https://digitalcommons.odu.edu/physics_fac_pubs/900