Abstract
Surface magnetism and its correlation with the electronic structure are critical to understanding the topological surface state in the intrinsic magnetic topological insulator MnBi2Te4. Here, using static and time resolved angle-resolved photoemission spectroscopy (ARPES), we find a significant ARPES intensity change together with a gap opening on a Rashba-like conduction band. Comparison with a model simulation strongly indicates that the surface magnetism on cleaved MnBi2Te4 is the same as its bulk state. The inability of surface ferromagnetism to open a gap in the topological surface state uncovers the novel complexity of MnBi2Te4 that may be responsible for the low quantum anomalous Hall temperature of exfoliated MnBi2Te4.
| Original language | English |
|---|---|
| Article number | 117205 |
| Journal | Physical Review Letters |
| Volume | 125 |
| Issue number | 11 |
| DOIs | |
| State | Published - Sep 2020 |
Funding
H. M. acknowledges M. H. Du, H. X. Fu, S. Okamoto, B. H. Yan, and T. T. Zhang for insightful discussions. Work at Brookhaven National Laboratory was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-SC0012704 (Laser-ARPES and data interpretation). Work at Oak Ridge National Laboratory (ORNL) was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division (sample synthesis and ARPES). H. M. and R. G. M. were supported by the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for the U. S. Department of Energy (ARPES and data interpretation).