Fluctuation-induced diamagnetism in bulk isotropicsuperconductors at high reduced temperatures

Abstract

The short-wavelength effects on the fluctuation-induced diamagnetism(FD) in bulk isotropic three-dimensional (3D) superconductors aretaken into account by introducing in the Gaussian-Ginzburg-Landauapproach different cut-off conditions. These calculations, whichextend to the 3D case our previous results on layeredsuperconductors, are then used to briefly analyse the FD datameasured for the low-temperature superconducting alloyPb-8 at.% In. These analyses confirm the adequacy of atotal-energy cut-off for explaining, for low-temperature 3Dsuperconductors also, the thermal fluctuation effects in thehigh-reduced-temperature region. These results thus provide furthersupport to the recent proposal that, due to the localization energy,the size of the effective fluctuations cannot be appreciably smallerthan the superconducting coherence length amplitude extrapolated toT = 0 K.