Breakdown of chiral edge modes in topological magnon insulators

Abstract

Topological magnon edge modes have been proposed for the realization of robust, low-loss spintronic devices. However, ubiquitous many-body interactions that do not preserve particle number significantly compromise their topological protection. The authors show here that these interactions can lead to significant edge mode damping, hybridization with bulk modes, and coupling between edge modes on opposite sides. These findings pose challenges for the experimental realization of topological magnon edge modes, but can be overcome by the application of large magnetic fields.