Pseudogap and its influence on normal and superconducting states of cuprates

A model incorporating simultaneous superconducting and lattice instabilities has been studied in detail to estimate the nature of coupling and inter-play between them. The phase diagram is obtained in the temperature-filling plane at different values of the parameters of the model. It is found that a pseudogap develops in the distorted phase that inhibits the appearance of the superconducting transition. The superconducting instability is strongest for the regime of filling where the van Hove singularity in the 2D density of states is close to the chemical potential. The pseudogap, developed in the distorted phase, is a function of temperature via the temperature dependence of the distortion itself. Transport properties, namely resistivity and thermopower are found to be strongly dependent on the variations of the pseudogap. PACS No. 74.25.Dw ,71.10.Hf ,74.20.Fg