Short Wavelength Cutoff Effects in the AC Fluctuation Conductivity of Superconductors

The short wavelength cutoff has been introduced in the calculation of ac fluctuation conductivity of superconductors. It is shown that a finite cutoff leads to a breakdown of the scaling property in frequency and temperature. Also, it increases the phase phi of the complex conductivity (tan(phi)=sigma_2/sigma_1) beyond pi/4 at T_c. Detailed expressions containing all essential parameters are derived for 3D isotropic and anisotropic fluctuation conductivity. In the 2D case we obtain individual expressions for the fluctuation conductivity for each term in the sum over discrete wavevectors perpendicular to the film plane.