Berry curvature and edge states on a ferromagnetic honeycomb lattice
Ferromagnetic honeycomb lattices with Dzyaloshinskii-Moriya (DM) interaction break time-reversal symmetry, giving magnon bands nonzero Chern numbers — a bosonic analog of the quantum Hall effect. Edge modes carry heat current without backscattering. Shown: magnon wavepacket circulating the lattice boundary.