Phase Diagram of a Three Orbital Model for the high-T$_c$ cuprates

TL;DR

This study maps the phase diagram of a three orbital model for high-Tc cuprates, revealing stable orbital current loops, antiferromagnetism, superconductivity, and Fermi-liquid phases through advanced computational methods.

Contribution

It introduces a detailed phase diagram for a three orbital model of cuprates, highlighting the stability of orbital current loops under specific conditions.

Findings

Orbital current loop state is stable in the thermodynamic limit.

Phase transitions from orbital current loops to AFM, SC, and FL phases with doping.

The model aligns with experimental Fermi surface features of hole-doped cuprates.

Abstract

We study the phase diagram of an effective three orbital model of the cuprates using Variational Monte-Carlo calculations (VMC) on asymptotically large lattices and exact diagonalization on a 24-site cluster. States with ordered orbital current loops (LC), itinerant Anti-ferromagnetism (AFM), d-wave superconductivity (SC), and the Fermi-liquid (FL) are investigated using appropriate Slater determinants refined by Jastrow functions for on-site and inter-site correlations. We find an LC state stable in the thermodynamic limit for a range of parameters compatible with the Fermi surface of a typical hole doped superconductors provided the transfer integrals between the oxygen atoms have signs determined by the effects of indirect transfer through the Cu-4s orbitals as suggested by O.K. Andersen. The results of the calculations are that this phase gives way at lower dopings to an AFM phase and at larger copings to a SC phase followed by a FL phase.