Exact stripe, checkerboard, and droplet ground states in two dimensions

TL;DR

This paper derives exact stripe, checkerboard, and droplet ground states in a 2D generalized periodic Anderson model, showing how additional Hamiltonian terms can eliminate droplet degeneracy and stabilize specific patterns.

Contribution

It provides the first exact solutions for nondegenerate stripe and checkerboard ground states in a 2D model, and demonstrates how to remove droplet states through Hamiltonian modifications.

Findings

Exact stripe and checkerboard ground states obtained

Droplet states eliminated by Hamiltonian extensions

Stable charge patterns identified below quarter filling

Abstract

Exact static nondegenerate stripe and checkerboard ground states are obtained in a two-dimensional generalized periodic Anderson model, for a broad concentration range below quarter filling. The random droplet states, also present in the degenerate ground state, are eliminated by extending the Hamiltonian with terms of different physical origin such as dimerization, periodic charge displacements, density waves, or distorsion lines.