Unidirectional magnetoresistance driven by nonreciprocal magnons

Conventional unidirectional magnetoresistance (UMR) requires a bilayer of magnetic and nonmagnetic layers with structural inversion asymmetry, working only when both magnetization and current are in the plane of layers. UMR in these systems is primarily driven by conduction electrons via current-induced spin polarization and spin-dependent scattering. In this work, we predict a novel UMR mechanism where nonreciprocal magnons play a central role. We show that magnon nonreciprocity, arising from relativistic spin-orbit coupling in chiral magnetic systems, induces nonreciprocal charge transport through electron-magnon interactions. This magnon-driven UMR offers key advantages, including enhanced magnitude, tunability, and compatibility with perpendicular magnetization configurations, making it promising for applications. We also discuss its realization in emerging magnetic materials like two-dimensional magnets and magnetic topological metals.