Disorder-induced trapping and anti-trapping of vortices in type-II superconductors

Abstract

We study the features of the superconductivity nucleation and vortex configurations in superconductors with modulated disorder. Using the Ginzburg-Landau-type theory with spatially varying diffusion coefficient, we uncover and explain the switching between the vortex-defect attraction to the repulsion upon the increase in the external magnetic field. It is shown that for rather weak applied magnetic fields, a superconducting nucleus localized near the region with the suppressed diffusion coefficient possesses a nonzero vorticity whereas the increase in the magnetic field can lead to a transition into the state with zero winding number. We demonstrate the manifestations of this switching phenomenon in superconductors with a large number of defects by performing numerical simulations of the vortex structures in superconductors with periodic spatial profiles of the diffusion coefficient. The obtained results clarify the physics of the vortex arrangement in several classes of the superconducting materials including one-dimensional superlattices and nanopatterned superconductors with regular arrays of the defects characterized by the increased concentration of nonmagnetic impurities.

13 pages, 9 figures

References in corpus (5)

• Stable large-scale solver for Ginzburg-Landau equations for superconductors
• Strong-pinning regimes by spherical inclusions in anisotropic type-II superconductors
• Effect of hexagonal patterned arrays and defect geometry on the critical current of superconducting films
• Direct visualization of vortex ice in a nanostructured superconductor
• Angular magnetic-field dependence of vortex matching in pinning lattices fabricated by focused or masked helium ion beam irradiation of superconducting YBa${}_2$Cu${}_3$O${}_{7-\delta }$ thin films

Cited by in corpus (1)

• Vortex structure and intervortex interaction in superconducting structures with intrinsic diode effect