Paraconductivity of three-dimensional amorphous superconductors-evidence for a short-wavelength cutoff in the fluctuation spectrum

Measurements of the temperature dependence and magnetic-field dependence of the paraconductivity of a three-dimensional amorphous superconductor are presented. The data are analyzed in terms of several current theories and are found to give good agreement for low fields and temperatures near Tc. Strong pair-breaking effects due to thermal phonons are believed to account for the observed absence of anomalous Maki-Thompson contributions to the paraconductivity. The paraconductivity falls well below predicted theoretical values in the high-temperature and high-field limits. This is attributed to the reduced role of high-wave-vector contributions to the paraconductivity. It is shown that the introduction of a short-wavelength cutoff in the theoretical fluctuation spectrum provides a phenomenological account of the discrepancy between theory and experiment. © 1978 The American Physical Society.