Axion insulator state in hundred-nanometer-thick magnetic topological insulator sandwich heterostructures.

ABSTRACT: An axion insulator is a three-dimensional (3D) topological insulator (TI), in which the bulk maintains the time-reversal symmetry or inversion symmetry but the surface states are gapped by surface magnetization. The axion insulator state has been observed in molecular beam epitaxy (MBE)-grown magnetically doped TI sandwiches and exfoliated intrinsic magnetic TI MnBi₂Te₄ flakes with an even number layer. All these samples have a thickness of ~ 10 nm, near the 2D-to-3D boundary. The coupling between the top and bottom surface states in thin samples may hinder the observation of quantized topological magnetoelectric response. Here, we employ MBE to synthesize magnetic TI sandwich heterostructures and find that the axion insulator state persists in a 3D sample with a thic

SUBMITTER: Zhuo D 

PROVIDER: S-EPMC10663498 | biostudies-literature | 2023 Nov

REPOSITORIES: biostudies-literature