Abstract
We report the use of a parallel magnetic field to suppress the superconducting gap and intergrain Josephson coupling in granular Al films. The critical field is spin paramagnetically limited, and the field induced superconductor-insulator (S-I) transition is found to go from second order to first order at 250 mK. In the vicinity of , the field reproduces the quasireentrance and super-resistive behavior seen in the zero-field S-I transition. We show that the super-resistive phase is dominated by Coulomb blockade.
- Received 11 April 1994
DOI:https://doi.org/10.1103/PhysRevLett.73.1412
©1994 American Physical Society