The interplay between localization and superconductivity has been studied in uniform ultrathin films of both high- and low-temperature superconductors. In both types, a decrease of the transition temperature with decreasing thickness and increasing sheet resistance is found, and there appears to be a critical sheet resistance for superconductivity. The important issue is whether the threshold is material-dependent, or universal, with a value close to the quantum resistance for pairs, h/4e2 (6450Ω), the value found for films of Bi and DyBaCuO. The universality of this result would have important implications for the fundamental understanding of this problem.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering