NONLINEAR MAGNETIZATION IN SUPERCONDUCTORS WITH S+D ORDERING

The nonlinear magnetization in the Meissner regime is considered withi n the Ginzburg-Landau theoretical framework. A calculational method in the case of conventional superconductors (one order parameter) is dev eloped and this method is extended for the case of two order parameter s (s+d mixing). In the mean field analysis, corrections to the penetra tion depth are of order H-02 where H-0 is the applied field. The aniso tropy in the penetration depth is calculated and the temperature depen dence of the magnetization is extracted. Signatures of the different o rdering possibilities are derived. We discuss the relevant experimenta l results in the light of these calculations.