Degenerate and chiral states in the extended Heisenberg model in the kagome lattice

TL;DR

This study investigates the low-temperature phases of an extended Heisenberg model on the kagome lattice, revealing degenerate and chiral states, effects of magnetic fields, and the influence of Dzyaloshinskii-Moriya interactions, highlighting complex frustrated magnetic behaviors.

Contribution

It provides a comprehensive analysis of degenerate and chiral states in the extended kagome Heisenberg model, including effects of external fields and DM interactions, with insights into spin liquid behavior.

Findings

Degenerate lines exhibit semi-extensive or extensive degeneracy.

External magnetic fields influence state selection and phase behavior.

Dzyaloshinskii-Moriya interactions lead to diverse low-temperature phases.

Abstract

We present a study of the low temperature phases of the antiferromagnetic extended classical Heisenberg model in the kagome lattice, up to third nearest neighbors. First, we focus on the degenerate lines in the boundaries of the well-known staggered chiral phases. These boundaries have either semi-extensive or extensive degeneracy, and we discuss the partial selection of states by thermal fluctuations. Then, we study the model under an external magnetic field on these lines and in the staggered chiral phases. We pay particular attention to the highly frustrated point, where the three exchange couplings are equal. We show that this point can me mapped to a model with spin liquid behavior and non-zero chirality. Finally, we explore the effect of Dzyaloshinskii-Moriya (DM) interactions in two ways: an homogeneous and a staggered DM interaction. In both cases, there is a rich low temperature phase diagram, with different spontaneously broken symmetries and non trivial chiral phases.