Topological properties of multilayer magnon insulators

The potential for topological excitations in 2D magnetic insulators has proven to be an exciting field in recent years. In a recently published work it was shown that rhombohedrally stacked, ferromagnetically coupled multilayers with alternating Dzyaloshinksii-Moriya interactions can host a multitude of topological phases[1]. These topological phases are characterized by their unique Chern numbers and sharp jumps in the thermal Hall conductance between phases. Motivated by experimental results, we extend the analysis of topological signatures in antiferromagnetically coupled and monoclinically stacked few layer 2D magnets. We report significant differences in the topological features between the rhombohedral and monoclinic stackings which may prove useful in characterizing magnetic multilayers grown for device applications.

[1] S. Hofer et al. Phys. Rev. B 104, 064427 (2021)