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Title: Electron mean free path dependence of the vortex surface impedance

In the present study the radio-frequency complex response of trapped vortices in superconductors is calculated and compared to experimental data previously published. The motion equation for a magnetic flux line is solved assuming a bi-dimensional and mean-free-path-dependent Lorentzian-shaped pinning potential. The resulting surface resistance shows the unprecedented bell-shaped trend as a function of the mean-free-path observed in our previous experimental work. We demonstrate that such bell-shaped trend of the surface resistance as a function of the mean-free-path may be described as the interplay of the two limiting regimes of the surface resistance, for low and large mean-free-path values: pinning and flux-flow regimes respectively. Since the possibility of defining the pinning potential at different locations from the surface and with different strengths, we discuss how the surface resistance is affected by different configurations of pinning sites. By tackling the frequency dependence of the surface resistance, we also demonstrate that the separation between pinning- and flux-flow-dominated regimes cannot be determined only by the depinning frequency. As a result, the dissipation regime can be tuned either by acting on the frequency or on the mean-free-path value.
 [1] ;  [1] ;  [2] ;  [2] ;  [3]
  1. Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Illinois Institute of Technology, Chicago, IL (United States)
  2. Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
  3. Illinois Institute of Technology, Chicago, IL (United States)
Publication Date:
Report Number(s):
Journal ID: ISSN 0953-2048; 1594851
Grant/Contract Number:
Published Article
Journal Name:
Superconductor Science and Technology
Additional Journal Information:
Journal Volume: 30; Journal Issue: 3; Journal ID: ISSN 0953-2048
IOP Publishing
Research Org:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
Country of Publication:
United States
43 PARTICLE ACCELERATORS; RF superconductivity; vortex; vortex dynamics; vortex dissipation; mean free path dependence
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1339473; OSTI ID: 1362051