Mechanism for flux guidance by micrometric antidot arrays in superconducting films

Flux distribution in superconducting films with holes

Flux penetration into type-II superconducting films is simulated for transverse applied magnetic field and flux creep dynamics. The films contain macroscopic nonconducting holes, and we introduce the holes in the simulation formalism by reconstruction of the magnetic field change inside the holes. We find that the holes induce a region of reduced flux density extending toward the nearest sample...

Magnetization reversal in cobalt antidot arrays

We have carried out a detailed study of the magnetic switching in square lattice cobalt antidot arrays with periods ranging from 2 m down to 200 nm antidot size=antidot separation . Magneto-optical Kerr effect measurements show first a small change in the magnetization due to a reversible rotation of the magnetic spins in the antidot rows, followed by a large change due to reversal of the antid...

Dendritic flux avalanches and nonlocal electrodynamics in thin superconducting films.

We report a mechanism of nonisothermal dendritic flux penetration in superconducting films. Our numerical and analytical analysis of coupled nonlinear Maxwell and thermal diffusion equations shows that dendritic flux pattern formation results from spontaneous branching of propagating flux filaments due to nonlocal magnetic flux diffusion and positive feedback between flux motion and Joule heati...

Unstable flux flow due to heated electrons in superconducting films.

A flux instability occurs in superconductors at low temperatures, where e-e scattering is more rapid than e-ph, whereby the dissipation significantly elevates the electronic temperature while maintaining a thermal-like distribution function. The reduction in condensate and rise in resistivity produce a nonmonotonic current-voltage response. In contrast to the Larkin-Ovchinnikov instability wher...

Dynamics and morphology of dendritic flux avalanches in superconducting films