Nonlinear Response above the Superconducting Transition Point. III

The nonlinear excess conductivity due to the pair fluctuation is recalculated in the Ginzburg-Landau-Gorkov approximation. The nonlinear effect is very sensitive to the purity of sample, and the reduction from the Aslamazov-Larkin formula is not small. The width of the transition becomes narrower in a pure sample due to the nonlinear effect. Discussions of the experiments and of the future problems are given. The possibility of applying the Langevin method to the Ginzburg-Landau equation is microscopically established in order to explain the critical phenomena in the classical range of temperature.