The Essential Characteristics of the Pseudogapped Metallic State of High-Tc Superconductor

Abstract

The pseudogapped metallic state which was recently revealed by angle-resolved photoemission experiments in the normal state of high-T c superconductor (HTS) can be interpreted with a model of non-simple metal in which there are locally correlating carrier pairs and the coexisting single itinerant carriers. The pair correlation is temperature dependent with a delocalization process with decreasing temperature down to T c , which can be revealed by the thermoelectric power S of HTS. By theoretical calculation, it is shown that a pseudogap exists in electronic energy spectrum of this two-component system in which high T c and small superconducting coherence length can be obtained in its superconducting state.