Abstract
Experimental support is found for the multiband model of the superconductivity in the recently discovered system with the transition temperature . By means of Andreev reflection, evidence is obtained for two distinct superconducting energy gaps. The sizes of the two gaps ( and ) are, respectively, smaller and larger than the expected weak coupling value. Because of the temperature smearing of the spectra the two gaps are hardly distinguishable at elevated temperatures, but when a magnetic field is applied the presence of two gaps can be demonstrated close to the bulk in the raw data.
- Received 18 June 2001
DOI:https://doi.org/10.1103/PhysRevLett.87.137005
©2001 American Physical Society