Proximity effect theories for metallic multilayers

Influence of the boundary resistivity on the proximity effect

“…[2][3][4][5][6][7] For the first solution, the fitted parameters are close to what one knows from the measurements. However, the dimensional crossover, typical for S/N multilayers, appeared to lie at a much higher temperature than the measured one.…”

Model calculations of the proximity effect in finite multilayers

“…This can be understood globally in terms of superconducting bulk properties. For a bulk superconductor the only eigenvalue that contributes in the determinant (6) is the ground state eigenvalue, which is proportional to the diffusion constant and the magnetic field, and inversely proportional to the magnetic flux quantum φ 0 = hc 2e [1,17,20],…”

“…They restricted their calculations to a particular class of systems, in which the component layers have the same T c , but different diffusion constants. To such systems, it was shown [2] that the Werthamer theory applies exactly. Similar results were obtained by Takanaka [8], but he initially started from the Takahashi-Tachiki theory.…”

“…One could describe either the thick layer limit, using Werthamer's approximation, or the thin layer limit, in which the Cooper-de Gennes description could be applied. The Takahashi-Tachiki formalism is a link between these two limits, offering the possibility to describe multilayer systems for intermediate thicknesses as well [2].…”

Minisubbands in electron excitation spectra of layered short-coherence-length superconductors

“…Really, in irregular metal oxide samples used in works, 17,18 the ratio c Ќ / Ќ ϳ1 and DB Ϸc Ќ ( DB is the electron de Broglie wave length͒. This means that the quasiclassical solution [24][25][26][27][28] itself could be dubious for the last mentioned case, while the problem should be handled self-consistently, for the details of the electron spectrum dependent on the ⌬(x) shape. A different approach was implemented in works 11,29 to calculate the electron spectrum of a multilayered metal oxide within the tunneling Hamiltonian formalism.…”