Critical temperature and interface transparency of N/S/N triple layers: theory and experiment

The influence of the finite transparency, <InlineEquation ID="Equ1"> <EquationSource Format="TEX">${\mathcal T}$</EquationSource> </InlineEquation>, of superconductor/normal metal (S/N) interface on the critical temperature of proximity coupled layered structures is investigated in the dirty limit on the basis of the microscopic equations solved exactly by a matrix method. The calculated theoretical curves satisfactory reproduce the experimental dependencies of the critical temperature on the thickness of the superconducting layers in N/S/N trilayers. The relation between the transparency coefficient and the normal metal coherence length is also discussed. Copyright EDP Sciences/Società Italiana di Fisica/Springer-Verlag 2006