Interaction between a cylindrical superconducting impurity and a vortex in a type-II superconductor
Journal
Physica C
Journal Volume
275
Journal Issue
1-2
Pages
135-140
Date Issued
1997
Author(s)
Abstract
We examined the effectiveness of an infinite cylindrical superconducting impurity of radius a in an infinite type-II superconductor as a pinning center. The impurity and the superconducting background have the penetration depth λi and λs, respectively. With regard to a single-quantum vortex, the free energy of the system and the pinning potential for a vortex were calculated, based upon the London model of the vortex line. Here, the pinning potential Upin is defined by the difference between the free energy of a vortex being at the center of the impurity and that being infinitely distant from the impurity. Upin is negative for λi > λs. On the other hand, Upin is positive for λi < λs. In the limit of a ≫ λi and λs, the pinning potential is found to be Upin = φ20(1/λ2i - 1/λ2s) In κ/4πμ0. In the limit of a ≪ γi and λs, the pinning potential is found to be Upin = φ20[(1/λ2i - 1/λ2ss) 1n κ + (1/λ2ss) 1n(λs/a) - (1/λ2i) 1n(λi/a)]/4πμ0. There is a clear correlation between the intrinsic property of these two superconducting materials and the pinning potential.
SDGs
Type
journal article