Pseudogap Induced by Superconducting Fluctuation in the d-p Model

抄録

Using the d-p model, we demonstrate that the pseudogap, which is induced by the superconducting fluctuation, plays key roles in the determination of the phase diagram observed in high-T_c superconducting materials. We take the pairing interaction mediated by the spin fluctuation and calculate the superconducting transition temperature T_c, the NMR relaxation rate 1/T₁ and the single-particle spectrum by treating both the superconducting fluctuation and spin fluctuation in a consistent fashion. As temperature decreases, 1/T₁T increases at high temperatures, and it reaches a maximum followed by a sharp drop in the underdoped region, due to the evolution of the pseudogap in the single-particle spectrum. The evolution is also consistent with those of ARPES experiments.