Symmetry-induced giant vortex state in a superconducting Pb film with a fivefold Penrose array of magnetic pinning centers.
A direct visualization of the flux distribution in a Pb film covering a fivefold 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 approximately 0.8H_{1}, H_{1}, and 1.6H_{1}, where H_{1} corresponds to one flux quantum per pinning site. The vortex pattern at 0.8H_{1} corresponds to one vacancy in one of the vertices of the thin tiles, whereas at 1.6H_{1} the vortex structure can be associated with one interstitial vortex inside each thick tile. Strikingly, for H = 1.6H_{1}, interstitial and pinned vortices arrange themselves in ringlike structures ("vortex corrals") which favor the formation of a giant vortex state at their center.
Kramer
R B G
RB
INPAC-Institute for Nanoscale Physics and Chemistry, Nanoscale Superconductivity and Magnetism Pulsed Fields Group, K. U. Leuven, B-3001 Leuven, Belgium.
Silhanek
A V
AV
Van de Vondel
J
J
Raes
B
B
Moshchalkov
V V
VV