Distinguishing the origin of the superconducting state from the pseudogap of high-temperature superconductors

TL;DR

This paper proposes that electronic phase separation causes inhomogeneous charge regions in high-temperature superconductors, leading to a phase boundary potential that influences superconducting properties and explains observed behaviors.

Contribution

It introduces a model linking phase separation and phase boundary potentials to the inhomogeneous superconducting gaps in cuprates, supported by self-consistent calculations.

Findings

Reproduces observed properties of superconducting cuprates.

Shows smaller superconducting gaps compared to pseudogap behavior.

Supports resistivity transition via Josephson coupling among grains.

Abstract

We consider an electronic phase separation process that generates regions of different charge densities, or local dopings, as the origin of the inhomogeneous charge density of high $T_c$ superconductors. We show that it gives rise to a phase boundary potential between such doping disordered regions or grains. The Bogliubov-deGennes self-consistent calculations in this disordered medium yield position dependent superconducting gaps which are, for all dopings, smaller than those derived from the local density of states with a pseudogap behavior. Studying these two sets of gaps for different temperatures and dopings, we are able to reproduce many many observed properties of superconducting cuprates. This scenario is consistent with a resistivity transition driven by Josephson coupling among the superconducting grains.