Pseudogap Regime in a BCS Bose–Einstein Crossover Scenario: Experimental Consequences and Tests

Abstract

We have argued that the pseudogap regime in the cuprates is characterized by the presence of metastable, long lived pairs which form the natural intermediate state between the free fermions of the BCS and bound pairs of the Bose Einstein limits. Here we investigate the experimental consequences associated with this resonant pair scattering in the normal state. The essential feature of these pair resonances is that they are dynamic pairing fluctuations. Of particular interest in distinguishing different scenarios for the cuprate pseudogap are probes which predominantly couple to the static and dynamic pair fluctuations, respectively. We therefore contrast the behavior of the diamagnetic susceptibility with the pair tunneling spectra of Superconductor-Pseudogapped cuprate junctions.