| Abstrakt: |
The Ginzburg{Landau (GL) theory is recast using a Hamiltonian involving the complete kinetic energy density which requires that the surface energy must contain a term ∇|ψ|[SUP2] to support superconducting (SC) states. The GL equations contain two temperature t dependent parameters α(t) and β(t), which are respectively the coefficients of the SC pair density &porp; |ψ|[SUP2], and the pair interaction term &porp; |ψ|[SUP4] in the free energy density. The sign of these parameters, which defines distinct solution classes, and the ratio s(t) = √|α|/|β| are governed by the characteristics of the surface energy density. In addition to the conventional bulk superconducting states with (α < 0, β > 0), anomalous superconducting states exist for all other sign combinations, including cases with β < 0 which may exist only when surface pair interactions are signi3cant. All possible solutions of our generalized nonlinear, one-dimensional GL equations are found analytically and applied to a thin superconducting slab which manifests the possibility of states exhibiting enhanced, diminished, and pre-wetting superconductivity. Critical currents are determined as functions of s(t) and surface parameters. The results are applied to critical current experiments on SNS systems. [ABSTRACT FROM AUTHOR] |
