Exact solutions of domain wall and spiral ground states in Hubbard models

TL;DR

This paper constructs exact ground states with ferromagnetic domain walls and spiral structures in a deformed flat-band Hubbard model, analyzing their stability and electron scattering properties.

Contribution

It introduces a set of exact solutions for complex magnetic structures in a Hubbard model, including stability analysis under perturbations.

Findings

Unique ground state at quarter filling with fixed magnetization

Stability of domain wall and spiral structures under band-bending perturbations

Electron scattering behavior by magnetic structures

Abstract

We construct a set of exact ground states with a localized ferromagnetic domain wall and an extended spiral structure in a deformed flat-band Hubbard model. In the case of quarter filling, we show the uniqueness of the ground state with a fixed magnetization. We discuss more realistic situation given by a band-bending perturbation, which can stabilize these curious structures. We study the scattering of a conduction electron by the domain wall and the spiral spins.