Phase Separation and the Dual Nature of the Electronic Structure in Cuprates

TL;DR

This paper investigates the dual electronic structure of cuprates, combining experimental ARPES data with phase separation theory to explain how disorder and stripe formation influence superconductivity and electronic properties.

Contribution

It applies the Cahn-Hilliard phase separation model to cuprates, linking disorder, stripe evolution, and superconducting gap behavior with experimental observations.

Findings

Disorder enhances local superconducting gaps.

Stripe size increases with doping, leading to metallic behavior.

Dual electronic features are explained by phase separation dynamics.

Abstract

The dual nature of the electronic structure of stripes in $La_{2-x}Sr_xCuO_4$ was characterized by experimental observations, mainly by ARPES, of nodal spectral weight together with the straight segments near antinodal regions. We present here an attempt to understand this dual behavior in terms of the competition of order and disorder, by applying the phase separation theory of Cahn-Hilliard (CH) to the high pseudogap temperature, which is very large in the far underdoping region and vanishs near the doping level p=0.2. The spinodal phase separation predictions together with the Bogoliubov-deGennes (BdG) superconducting theory provides several interesting insights. For instance, we find that the disorder enhances the local superconducting gap which scales with the leading edge shift and that, upon doping, the size of the hole-rich stripes increases, yielding to the system their metallic properties.