Hartree-Fock Computation of the High-Tc Cuprate Phase Diagram

TL;DR

This paper presents a Hartree-Fock computational model of the cuprate phase diagram, accurately predicting various experimental phenomena and suggesting superexchange as the key interaction.

Contribution

It introduces a Hartree-Fock based approach with symmetry constraints to model the cuprate phase diagram, fitting key parameters to experimental data.

Findings

Quantum phase transitions at 5% and 16% doping

Insulating behavior below 5% doping

D-wave pseudogap spectrum and related properties

Abstract

A computation of the cuprate phase diagram is presented. Adiabatic deformability back to the density function band structure is assumed. Symmetry constraints lead to a fermi liquid theory with 5 interaction parameters. Two of these are forced to zero by experiment. The remaining 3 are fit to (1) the moment of the antiferromagnetic state at half filling, (2) the superconducting gap at optimal doping, and (3) the maximum pseudogap, which I identify as d-density wave. Solution of the Hartree-Fock equations gives, in quantitative agreement with experiment, (1) quantum phase transitions at 5% and 16% p-type doping, (2) insulation below 5%, (3) a d-wave pseudogap quasiparticle spectrum, (4) pseudogap and superconducting gap values as a function of doping, (5) superconducting Tc versus doping, (6) London penetration depth versus doping, (7) spin wave velocity. The fit points to superexchange mediated by the bonding O atom in the Cu-O plane as the causative agent of all three ordering phenomena.