Proximity effects and vortex dynamics in superconducting heterostructures

CARREIRA, SANTIAGO ; BEKERIS VICTORIA; ROSEN, YANIV; SCHULLER IVAN

Buenos Aires

Conferencia; International Conference in Low Temeprature Physics; 2014

Departamento de Física, FCEyN, UBA

Vortex lattice dynamics has been studied in thin Nb superconducting films sputtered on top of a dense triangular array of V dots with and without an intermediate SiO2 insulating layer. The insulating layer, although does not strongly modify the Nb film corrugation, reduces commensurability effects that seem dominated by proximity effects. Moreover, for the sample with no insulating layer, the phase diagram HC2 (T) shows a parabolic temperature dependence near TC and critical temperature oscillations with the periodicity of the matching field, implying that strong proximity effects locally suppress superconductivity leading to a superconducting mesh. In the second case, the insulating layer impedes proximity effects, and HC2(T) follows, consistently, the bulk linear T dependence.