A model with electron–phonon interaction for high-Tc d-wave cuprates

Abstract

Within the BCS framework a model with d-wave symmetry is introduced to describe high-Tc superconductor cuprates. The electron–phonon interaction is considered as the dominant cause of superconductivity. In order to increase the electronic density of states at the Fermi level, an anomalous occupation, has been proposed. The phonon available energy is introduced by the half-breathing phonons. Numerical results for the coupling parameter λ, the energy gap Δ0, and parameters of the model, as a function of doping, in the (0.105, 0.22) range, are obtained for the cuprate La2−xSrx CuO4. The λ values obtained are in the intermediate and the weak coupling region and the experimental results for the gap Δ0 are reproduced with our model.