Influence of the atomic scale inhomogeneity of the pair interaction on the local pair formation and density of states in high-T_c superconductors
Abstract
Description
The influence of the atomic-scale inhomogeneities of the pairing interaction on the superconducting order parameter distribution and the LDOS is studied in the framework of mean-field BCS theory for two-dimensional lattice model. It is found that the ratio of the local low-temperature gap in differential conductance to the local temperature of vanishing the gap $2Δ_g/T_p$ can take large enough values compared to the homogeneous case. This ratio practically does not depend on the location in the sample and is independent on the concentration of local pair interaction perturbations in wide range of concentrations. The obtained results could bear a relation to the recent measurements by Gomes {\it et. al} Nature, 447, 569 (2007).
5 pages, 3 figures, reference is added
5 pages, 3 figures, reference is added