Symmetry-induced giant vortex state in a superconducting film with a Penrose array of magnetic pinning centers
Abstract
A direct visualization of the flux distribution in a Pb film covering a five-fold Penrose array of Co dots is obtained by mapping the local field distribution with a scanning Hall probe microscope. We demonstrate that stable vortex configurations can be found for fields H~0.8H1, H1 and 1.6H1, where H1 corresponds to one flux quantum per pinning site. The vortex pattern at 0.8H1 corresponds to one vacancy in one of the vertices of the thin tiles whereas at 1.6H1 the vortex structure can be associated with one interstitial vortex inside each thick tile. Strikingly, for H=1.6H1 interstitial and pinned vortices arrange themselves in ring-like structures ("vortex corrals") which favor the formation of a giant vortex state at their center.
0