Theory of Extrinsic and Intrinsic Tunnelling in Cuprate Superconductors

TL;DR

This paper presents a comprehensive theory explaining the tunnelling conductance in underdoped cuprates, accounting for two energy scales, asymmetry, inhomogeneity, and temperature/doping dependencies of gaps.

Contribution

It introduces a novel theoretical framework that unifies the understanding of intrinsic and extrinsic tunnelling phenomena in cuprate superconductors.

Findings

Explains asymmetry and inhomogeneity in tunnelling conductance.

Accounts for temperature and doping dependence of energy gaps.

Describes the relationship between superconducting gap and pseudogap.

Abstract

A theory capable of explaining intrinsic and extrinsic tunnelling conductance in underdoped cuprates has been devised that accounts for the existence of two energy scales, their temperature and doping dependencies. The asymmetry and inhomogeneity seen in extrinsic (normal metal - superconductor (NS)) tunnelling and the normal-state gapped intrinsic (SS) conductance is explained, as well as the superconducting gap and normal state pseudogap and the temperature dependence of the full gap.