Magnetic and charge orders in the ground state of the Emery model -- accurate numerical results

TL;DR

This study uses advanced quantum Monte Carlo methods to accurately analyze the ground-state charge and spin orders in the Emery model, revealing asymmetry between electron and hole doping in cuprates.

Contribution

It introduces a high-precision AFQMC approach with a self-consistent gauge constraint to study complex orders in the Emery model at large scales.

Findings

Electron-doped systems show purely antiferromagnetic order.

Charge and spin orders depend on charge-transfer energy.

Results highlight asymmetry between electron and hole doping in cuprates.

Abstract

We perform extensive auxiliary-field quantum Monte Carlo (AFQMC) calculations for the three-band Hubbard (Emery) model in order to study the ground-state properties of Copper-Oxygen planes in the cuprates. Employing cutting-edge AFQMC techniques with a self-consistent gauge constraint in auxiliary-field space to control the sign problem, we reach supercells containing around 500 atoms to capture collective modes in the charge and spin orders and characterize the behavior in the thermodynamic limit. The self-consistency scheme interfacing with generalized Hartree-Fock calculations allows high accuracy in AFQMC to resolve small energy scales, which is crucial for determining the complex candidate orders in such a system. We present detailed information on the charge order, spin order, momentum distribution, and localization properties as a function of charge-transfer energy for the the under-doped regime. In contrast with the stripe and spiral orders under hole-doping, we find that the corresponding 1/8 electron-doped system exhibits purely antiferromagnetic order in the three-band model, consistent with the asymmetry between electron and hole-doping in the phase diagram of cuprates.