Anomalous Parallel Field Negative Magnetoresistance in Ultrathin Films   Near the Superconductor-Insulator Transition
  A parallel field negative magnetoresistance has been found in quench-condensed ultrathin films of amorphous bismuth in the immediate vicinity of the thickness-tuned superconductor-insulator transition. The effect appears to be a signature of quantum fluctuations of the order parameter associated with the quantum critical point. 
Kevin A. Parendo, L. M. Hernandez, A. Bhattacharya, A. M. Goldman