Resonant Tunneling, Pseudo-Gap, and Charge Dynamics in Cuprate Superconductors

Abstract

The quasi-two-dimensional, metallic conduction in the CuO2 planes and activated out-of-plane conduction seem typical for most of the cuprate superconductors. The counteraction of overlap and charging energies ΔU* yield the activated out-of-plane resonant tunneling in the normal state and the Josephson tunneling in the superconducting state which is quantitatively described by accepted parameters for various cuprate superconductors and oxygen contents. In addition, the localized, out-of-plane charge exchange obstructed by ΔU* of states of the blocking layer may explain spectroscopic observations, like the tunnel or the photoelectron pseudo-gap, or may scatter phonons and in-plane quasi-particles. The latter relates ΔU*≃kT* to the in-plane pseudo-gap temperature T*, where the scattering rate decreases below T* because of the obstructed out-of-plane exchange.