Relationships between the superconducting gap , pseudogap and transition temperature in high - T c superconductors

Relationships between the superconducting gap, pseudogap and transition temperature in high-T c superconductors Abstract The crossover from superconducting gap to pseudogap is considered. We show that the superconductivity is destroyed at the temperature T c , with the superconducting gap being smoothly transformed into the pseudogap. Relations, which are of general interest, between the maximum values of the gap ∆ 1 , T c and T * are established. We presents arguments that T * as a function of the doping level x is approximately a straight line that crosses the abscissa at some point x F C. In the vicinity of this point T * coincides with T c , and at x = x F C the fermion condensation quantum phase transition takes place.