Stripe formation in high-Tc superconductors

TL;DR

This study uses variational Monte Carlo to explore stripe formation in high-Tc superconductors, revealing how hole doping induces spin modulations and incommensurate structures consistent with experimental observations.

Contribution

It demonstrates that holes in the three-band Hubbard model stabilize stripe and spin modulation structures, providing a theoretical explanation aligned with neutron-scattering data.

Findings

Stripe and spin modulations are stabilized by hole doping.

Incommensurability correlates with hole density.

Results align with experimental neutron-scattering observations.

Abstract

The non-uniform ground state of the two-dimensional three-band Hubbard model for the oxide high-Tc superconductors is investigated using a variational Monte Carlo method. We examine the effect produced by holes doped into the antiferromagnetic (AF) background in the underdoped region. It is shown that the AF state with spin modulations and stripes is stabilized du to holes travelling in the CuO plane. The structures of the modulated AF spins are dependent upon the parameters used in the model. The effect of the boundary conditions is reduced for larger systems. We show that there is a region where incommensurability is proportional to the hole density. Our results give a consistent description of stripes observed by the neutron- scattering experiments based on the three-band model for CuO plane.