Hole clustering and mutual interplay in three-band Hubbard model

TL;DR

This study uses determinant Quantum Monte Carlo simulations to explore how a 4x4 supercell influences local charge order and pairing in a three-band Hubbard model, shedding light on mechanisms behind cuprate superconductivity.

Contribution

It provides the first numerical evidence supporting the significance of 4x4 supercells in hole-doped cuprates for local charge and pairing phenomena.

Findings

The 4x4 supercell acts as a fundamental unit in hole-doped cuprates.

Local spectra around the supercell indicate enhanced pairing tendencies.

Charge density distributions support the supercell's role in superconductivity.

Abstract

Recent scanning tunnelling spectroscopy (STS) experiments revealed remarkable role of a supercell consisting $4\times4$ CuO$_2$ unit cells in the emergence of local nematic state and preformed local Cooper pairs and phase coherent cuprate superconductivity. By employing the numerically exact determinant Quantum Monte Carlo simulations, we mimic the effects of experimental Ca vacancy by an external local potential to investigate the charge and spectral properties of the system hosting two doped holes. The model numerically support the role of the $4\times4$ supercell as the building block of hole doped cuprates via the hole density distribution and local spectra around the local potential. Our results might provide a theoretical support on the experimental observations and a platform for investigating local charge order and local Cooper pairs on the $4\times4$ supercell as the plausible route to understanding unconventional cuprate superconductivity.