Thermodynamic phase diagram of the competition between superconductivity and charge order in cuprates

TL;DR

This paper explores the complex interplay between superconductivity and charge order in cuprates, revealing a special doping point where these phases are degenerate and examining how disorder influences their competition.

Contribution

It introduces a Monte Carlo simulation to study the phase competition in cuprates, highlighting the effects of quenched disorder on phase separation and domain formation.

Findings

Charge order and superconductivity are degenerate at a special doping point.

Disorder fragments charge order into domains with superconducting filaments.

The simulated phase diagram aligns well with experimental observations.

Abstract

We argue that there is a special doping point in the phase diagram of cuprates, such that the condensation of holes into a charge-ordered and into a superconducting phase are degenerate in energy but with an energy barrier in between. We present a Monte Carlo simulation of this problem without and with quenched disorder. While in the clean case charge order and superconductivity are separated by a first-order line which is nearly independent of temperature, in the presence of quenched disorder, charge order is fragmented into domains separated by superconducting filaments reminiscent of the supersolid behavior in $^4$He. The resulting phase diagram is in good agreement with the experiments.