Role of boundary conditions in improving the working characteristics of superconductor-based nanostructures
Serghej L. Prischepa
, 
, a, V. N. Kushnira and C. Attanasiob
a State University of Informatics and RadioElectronics, P. Browka str. 6, Minsk 220013, Belarus
b Physics Department `E.R. Caianiello', University of Salerno, via S. Allende, 84081, Baronissi (SA), Italy
Available online 14 June 2003.
We examined the effect of boundary conditions on the critical parallel magnetic field Hc2|| and the critical current density Jc in superconductor-based nanostructures. For superconductor–normal metal superlattices, we observed the influence of the finiteness of the multilayers on the Hc2|| values. The result depends on the actual symmetry of the system. When the symmetry plane is in the center of the superconductor layer, Hc2|| is larger at high temperatures with respect to the situation when the symmetry plane is in the center of nonsuperconductor layers. For superlattices with an regular array of antidotes, we observed the sudden increase in the critical current at T=2.18 K. The effect could be explained in terms of larger pinning efficiency at the antidote–multilayer boundary due to the wetting of the antidotes below 2.18 K. The results of this work indicate the importance of the boundary conditions on the critical parameters of superconductor-based nanostructures.
Author Keywords: Superconducting nanostructure; Upper critical magnetic field; Critical current density; Geometrical symmetry; Antidote
