Pure magnon valley currents in a patterned ferromagnetic thin film

Abstract

We propose a new method to generate pure magnon valley currents in ferromagnetic thin films with triangular antidot lattices. We find that inhomogeneous distortions can generate pseudomagnetic fields which can be up to 60 $\mathrm{T}$ for magnons, and give rise to well-defined Landau levels. The pseudomagnetic fields push magnons at different valleys $\mathrm{K}$ and ${\mathrm{K}}^{\ensuremath{'}}$ transversely to opposite directions and accumulate at opposite edges, leading to magnon valley Hall effect and forming pure magnon valley edge currents. We also find that the oppositely directed pseudomagnetic fields result in magnon snake states at the center of the ribbon, forming pure magnon valley currents. Our work might pave a new way to manipulate magnon transport by using artificial designed structures.