Superconducting fluctuations at low temperature

The effect of fluctuations on the transport and thermodynamic properties of two-dimensional superconductors in a perpendicular magnetic field is studied at low temperature T much less thanT(c0). The fluctuation conductivity is calculated in the framework of perturbation theory with the help of the usual diagram technique. It is shown that in the dirty case the Aslamazov-Larkin, Maki-Thompson, and density of states contributions are of the same order. At extremely low temperature T/T-c0 much less than [H - H-c2(O)]/H-c2(0) the total fluctuation correction to the normal conductivity is negative in the dirty limit and depends on the external magnetic field logarithmically delta sigma proportional to ln[H - H-c2(0)]. In the nonlocal clean limit, the Aslamazov-Larkin contribution to conductivity is evaluated with the aid of Helfand-Werthamer theory. The longitudinal and Hall conductivities are found. The fluctuating magnetization is calculated in the one-loop and two-loop approximations.