Nonlinear fluctuation phenomena in the transport properties of superconductors

There exists a wide temperature region (GiT < T - T-c < T root Gi) where th e influence of fluctuations on the thermodynamic properties of superconduct ors can be taken into account in the linear (Gaussian) approximation, while their influence on the kinetic properties is strongly nonlinear. The Maki- Thompson contribution to the conductivity saturates in this region. However , the Aslamazov-Larkin contribution becomes even more singular. This enhanc ement is related to the fact that nonlinear effects increase the lifetime o f fluctuating pairs. The pair breaking and energy relaxation processes can decrease the nonlinear effects. (C) 2001 MAIK "Nauka/Interperiodica".