From quantum corrections to magnetic-field-tuned superconductor-insulator quantum phase transition in TIN films

Results of the measurements of the magnetic-field-dependent resistance of ultrathin superconducting TiN films with different degrees of disorder are presented. The main features of the isomagnetic data R(T, B = const) and isotherms R(B, T = const) observed in all samples are: fan-shaped structure of R(T, B = const) curves, a negative magnetoresistance at high magnetic fields, the presence of an intersection point (B-C,R-C), and the possibility of a scaling data presentation. The analysis of the data reveals that such behavior, previously regarded as the main evidence of the magnetic-field-tuned superconductor-insulator transition, can actually be observed for a usual thermodynamic superconductor-normal metal transition, provided that the behavior of this metal is controlled, to a considerable degree, by the quantum corrections to the conductivity. (c) 2005 Elsevier B.V. All rights reserved.