Double-dimensional crossover in layered superconductor

Abstract

The critical magnetic fields Hc2 of superconducting layered structures V/Cu were investigated. The double-dimensional crossover 3D-2D-3D was observed on the temperature (H′c2(θ)) dependences of critical magnetic fields. The field crossover 3D-2D is caused by strong temperature dependence of superconducting coherence length ξs near Tc. The second crossover 2D-3D is provided by temperature dependence of normal metal coherence length ξN and reflects the 3D isotropization of layered structure V/Cu at low temperature.