Scanning Tunneling Microscope Study on the Intrinsic Antiferromagnetic Topological Insulator EuSn2As2

Syu-You Guan^2*, Yue Shi¹, Wen-Yu Chen², Jiun-Haw Chu¹, Tien-Ming Chuang²

¹Department of Physics, University of Washington, Seattle, Washington, USA
²Institute of Physics, Academia of Sinica, Taipei, Taiwan

* Presenter:Syu-You Guan, email:r95222038@gmail.com

Magnetic topological insulators (MTIs) have attracted great attention because they can exhibit exotic phenomena, such as quantum anomalous Hall effect and topological magneto-electric effect. Here, we focus on EuSn2As2, which is predicted to be an antiferromagnetic topological insulator and exhibits an axion insulator state. By using our home-built low-temperature scanning tunneling microscope, we have observed the strong spatial variation of the local density of states in real space. The electronic band structure of EuSn2As2, which was resolved by using the quasiparticle scattering interference imaging and DFT calculation, is greatly affected by the electronic inhomogeneity. We will discuss the potential impact on the band structure of EuSn2As2 by magnetic order.

Keywords: Magnetic Topological Insulators, Scanning Tunneling Microscopy, Surface Science, Topological Materials