Changes of Magnetism in a Magnetic Insulator due to Proximity to a Topological Insulator
Tao Liu, James Kally, Timothy Pillsbury, Chuan‐Pu Liu, Houchen Chang, Jinjun Ding, Yang Cheng, Maria Hilse, Roman Engel‐Herbert, Anthony Richardella, Nitin Samarth, Mingzhong Wu
Abstract
We report the modification of magnetism in a magnetic insulator Y_{3}Fe_{5}O_{12} thin film by topological surface states (TSS) in an adjacent topological insulator Bi_{2}Se_{3} thin film. Ferromagnetic resonance measurements show that the TSS in Bi_{2}Se_{3} produces a perpendicular magnetic anisotropy, results in a decrease in the gyromagnetic ratio, and enhances the damping in Y_{3}Fe_{5}O_{12}. Such TSS-induced changes become more pronounced as the temperature decreases from 300 to 50 K. These results suggest a completely new approach for control of magnetism in magnetic thin films.