Superconducting fluctuation, localization and electron–electron interaction corrections to the magnetoconductivity in three-dimensional aluminum films

The magnetoconductivity (MC) of three-dimensional (3D) aluminum films with various dirtiness has been measured in wide ranges of temperature and magnetic field. (1) Near the superconducting transition temperature T c , the MC takes the minimum at a temperature-independent field H m0 . (2) Above H m0 , MC shows H 1/2 dependence. From the detailed analysis of the H dependence of MC, it has been found that the magnitude of the coefficient of H 1/2 can be explained qualitatively by only the sum of contribution from the weak localization and electron–electron interaction. This experimental result indicates that the superconducting thermal fluctuation effect in the field is almost suppressed by this finite field H m0 , of which values are about two times as large as that of the mean-field upper critical field H c2 (0) as we reported for 2D aluminum films. This circumstance is consistent with the observation of a rapid suppression of the excess conductivity around 2 H c2 (0) for 3D type II superconductors by Lue et al. [J.W. Lue, A.G. Montgomery, R.E. Hake, Phys. Rev. B 11 (1975) 3393].