Document Type
Article
Publication Date
2013
DOI
10.1103/PhysRevB.87.054502
Publication Title
Physical Review B
Volume
87
Issue
5
Pages
054502
Abstract
We present detailed experimental and theoretical investigations of hotspots produced by trapped vortex bundles and their effect on the radio-frequency (rf) surface resistance Rs of superconductors at low temperatures. Our measurements of Rs, combined with the temperature mapping and laser scanning of a 2.36-mm-thick Nb plate incorporated into a 3.3-GHz Nb resonator cavity cooled by the superfluid He at 2 K, revealed spatial scales and temperature distributions of hotspots and showed that they can be moved or split by thermal gradients produced by the scanning laser beam. These results, along with the observed hysteretic field dependence of Rs which can be tuned by the scanning laser beam, show that the hotspots in our Nb sample are due to trapped vortex bundles which contain ~ 10⁶ vortices spread over regions ~ 0.1-1 cm. We calculated the frequency dependence of the rf power dissipated by oscillating vortex segments trapped between nanoscale pinning centers, taking into account all bending modes and the nonlocal line tension of the vortex driven by rf Meissner currents. We also calculated the temperature distributions caused by trapped vortex hotspots, and suggested a method of reconstructing the spatial distribution of vortex dissipation sources from the observed temperature maps. Vortex hotspots can dominate the residual surface resistance at low temperatures and give rise to a significant dependence of Rs on the rf field amplitude Hp, which can have important implications for the rf resonating cavities used in particle accelerators and forthin-film structures used in quantum computing and photon detectors.
Rights
© 2013 American Physical Society
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Original Publication Citation
Gurevich, A., & Ciovati, G. (2013). Effect of vortex hotspots on the radio-frequency surface resistance of superconductors. Physical Review B, 87(5), 054502. https://doi.org/10.1103/PhysRevB.87.054502
ORCID
0000-0003-0759-8941 (Gurevich)
Repository Citation
Gurevich, A. and Ciovati, G., "Effect of Vortex Hotspots on the Radio-Frequency Surface Resistance of Superconductors" (2013). Physics Faculty Publications. 901.
https://digitalcommons.odu.edu/physics_fac_pubs/901
