Evolution of magnetic Dirac bosons in a honeycomb lattice

TL;DR

This paper investigates how magnetic Dirac nodes evolve in a honeycomb lattice using linear spin theory, revealing their dependence on magnetic structure and exchange interactions, and demonstrating tunability via external parameters.

Contribution

It introduces a detailed analysis of magnetic Dirac and Weyl points in the Heisenberg honeycomb lattice, highlighting their relation to magnetic structure rather than crystal symmetry.

Findings

Ferromagnetic structures produce bosonic Dirac and Weyl points.

Magnetic Dirac nodes are linked to magnetic structure, not crystal symmetry.

Exchange interactions can tune the position and existence of Dirac nodes.

Abstract

We examine the presence and evolution of magnetic Dirac nodes in the Heisenberg honeycomb lattice. Using linear spin theory, we evaluate the collinear phase diagram as well as the change in the spin dynamics with various exchange interactions. We show that the ferromagnetic structure produces bosonic Dirac and Weyl points due to the competition between superexchange interactions. Furthermore, it is shown that the criteria for magnetic Dirac nodes are coupled to the magnetic structure and not the overall crystal symmetry, where the breaking of inversion symmetry greatly affects the antiferromagnetic configurations. The tunability of the nodal points through variation of the exchange parameters leads to the possibility of controlling Dirac symmetries through an external manipulation of the orbital interactions.