Molecular beam epitaxy growth and nanoscale characterization of antiferromagnetic topological insulator MnBi2Te4 thin films

MnBi2Te4 has recently attracted a lot of interest as the first intrinsic antiferromagnetic topological insulator. The majority of experiments thus far have focused on the synthesis and exploration of bulk single crystals and exfoliated flakes of MnBi2Te4. However, growing and studying high-quality thin films of MnBi2Te4 down to a single unit cell thickness remains a challenge. In this talk, I will discuss our experiments exploring the growth of MnBi2Te4 thin films of various thicknesses using molecular beam epitaxy (MBE). We use atomic force microscopy, X-ray diffraction and in-situ reflection high-energy electron diffraction to analyze the structural properties of MnBi2Te4 films. We perform magnetization measurements to probe its magnetic transition. We further investigate the electronic structure by using scanning tunneling microscopy and spectroscopy. Our work explores the possibility of fabricating ultra-thin films of magnetic topological insulators, which should be of high interest for future applications.