Research: Identifying and Constructing Complex Magnon Band Topology

In a crystalline ordered magnet, coherent excitations called spin waves, or magnons, propagate in the material forming band structures in an analogous way to electrons. Spin waves can possess non trivial topology associated with novel response functions of fundamental and potential technological interest. In particular, topologically protected surface states of magnons offer a new path towards coherent spin transport for spintronics applications. One of the central issues in this area is to establish the conditions under which band topology can arise in magnons and explore its variety. Researchers from Max Planck Institute for the Physics of Complex Systems (MPI-PKS) in Dresden, Germany, harness the full power of symmetry as applied to magnetism, to facilitate the discovery of new topological magnon models and materials. The efficient identification of such systems is obtained by adapting the electronic topological quantum chemistry scheme to magnons, using constraints imposed by time reversal and crystalline symmetries to determine possible gapped and nodal topology in magnon models.

A. Corticelli, R. Moessner, P. A. McClarty,
Identifying and Constructing Complex Magnon Band Topology,
Phys. Rev. Lett. 130, 206702 (2023) (arXiv)