Distinguishing surface and bulk electromagnetism via their dynamics in an intrinsic magnetic topological insulator.

ABSTRACT: The indirect exchange interaction between local magnetic moments via surface electrons has been long predicted to bolster the surface ferromagnetism in magnetic topological insulators (MTIs), which facilitates the quantum anomalous Hall effect. This unconventional effect is critical to determining the operating temperatures of future topotronic devices. However, the experimental confirmation of this mechanism remains elusive, especially in intrinsic MTIs. Here, we combine time-resolved photoemission spectroscopy with time-resolved magneto-optical Kerr effect measurements to elucidate the unique electromagnetism at the surface of an intrinsic MTI MnBi₂Te₄. Theoretical modeling based on 2D Ruderman-Kittel-Kasuya-Yosida interactions captures the initial quenching of a su

SUBMITTER: Nguyen KD 

PROVIDER: S-EPMC11313949 | biostudies-literature | 2024 Aug

REPOSITORIES: biostudies-literature