We present a spin wave picture for a-RuCl3, a material with significant Kitaev interaction. Strong anisotropic terms lead to three-magnon interaction that we estimate with a simple approach, without a rigorous calculation of the vertex, solving Dyson’s equation self-consistently. Turns out it matches experiment and numerics pretty well. Additional contribution of longitudinal fluctuations improves the agreement.
In this paper we study triangular-lattice antiferromagnet with anisotropic interactions. We explore the phase diagram with parameters of next-nearest neighbor exchange and pseudo-dipolar terms. As we find out they both prefer collinear stripe order but small disorder in the latter can lead to coexistence of different stripe domains. This picture is coexistent with recent neutron-scattering experiments on YbMgGaO4.
In this paper we study kagome ferromagnet with Dzyaloshinskii-Moriya interaction. As we find, even though the phase is polarized and stable, DM interaction induces quantum fluctuations that depend on the direction of magnetization. Three-magnon interactions lead to finite lifetime of topological modes. The question arises: how do we describe topological excitations in the presence of strong interactions?
Check out our paper on magnon decays in a field-induced umbrella phase of the triangular lattice XXZ antiferromagnet.