Affiliation
II. Institute of Physics, RWTH Aachen University
Title
Magnetism meets topology: The ferromagnetic topological insulator MnSb2Te4
Abstract
Slightly Mn rich MnSb$_2$Te$_4$ turns out to be a ferromagnetic topological insulator with the Dirac point of the topological surface state close to the Fermi level and gapped by on average 15 meV at 4 K. The gap disappears rather precisely at the Curie temperature of 45 K, such that the material provides an excellent model system where magentic properties are tight to the topology [1]. We investigated the spatial distribution of the magnetic gap, its partial closure by an external in-plane magnetic field and its spatiotemporal fluctuations at elevated temperature by scanning tunneling spectroscopy [2]. I will discuss the results that point to a rather complex magnetic interaction driven by the Mn atoms in the Sb layer that also turn out to be cruicial for the favorable magnetic and topological properties .
[1] Adv. Mater. 33, 2102935 (2021)
[2] ArXiv:2107:04428