Room-Temperature Switching of Perpendicular Magnetization by Magnon Torques

Electron-mediated spin torque provides a fast and efficient method to manipulate magnetization; how-ever, electron motion inevitably brings about the generation of Joule heat and corresponding power consumption. Magnon-mediated spin torque, without involving moving electrons, could circumvent the energy dissipation issue. In this work, we fabricate a sandwich structure of topological insula-tor/antiferromagnetic insulator/ferromagnet with perpendicular magnetic anisotropy. We find that the magnon current with spin angular momentum can traverse a 25-nm-thick antiferromagnetic NiO layer and effectively switch the perpendicular magnetization of Co-Fe-B at room temperature with a critical switching current density of 4.1 x 10(6) A/cm(2). The magnon torque efficiency is characterized using spin -torque ferromagnetic resonance measurements to be 0.33 with a magnon diffusion length of 26.6 nm. Our work paves the way for manipulating perpendicular magnetization via magnon torques, facilitating the exploration of magnon-based spintronics with low power consumption.