The Misfit Strain Critical Point in the 3D Phase Diagrams of Cuprates

TL;DR

This paper introduces a 3D phase diagram for cuprates incorporating misfit strain, doping, and temperature, revealing a quantum critical point linked to stripe phase transitions affecting high-temperature superconductivity.

Contribution

It proposes a unified 3D phase diagram including misfit strain as a key variable and formulates a model to identify the stripe quantum critical point in cuprates.

Findings

Identification of the stripe quantum critical point at (delta)c=1/8 and (eta)c=7%

Description of the phase diagrams for magnetic and superconducting orders across cuprates

A formula describing the Tc surface as a function of doping and misfit strain

Abstract

At the time of writing, data have been reported on several hundred different cuprates materials, of which a substantial fraction show superconductivity at temperatures as high as 130 K. The existence of several competing phases with comparable energy shows up in different ways in different materials, therefore it has not been possible to converge toward a universal theory for high Tc superconductivity. With the aim to find a unified description the Aeppli-Bianconi 3D phase diagram of cuprates has been proposed where the superlattice misfit strain (eta) is the third variable beyond doping (delta) and temperature T. The 3D phase diagrams for the magnetic order, and for the superconducting order extended to all cuprates families are described. We propose a formula able to describe the Tc (delta,eta) surface, this permits to identify the stripe quantum critical point at (delta)c=1/8 and (eta)c =7percent which is associated with the incommensurate to commensurate stripe phase transition, controlled by the misfit strain.