Coexistence of a Gapless Topological State and Surface Ferromagnetism in MnBi<sub>2</sub>Te<sub>4</sub>
ORAL
Abstract
The recent discovery of the intrinsic magnetic topological insulator MnBi2Te4 has sparked considerable interest because of the novel quantum properties that can arise as a result of the coupling between the topological and magnetic properties. However, the inability of the magnetic ordering to open a gap at the Dirac point, in contradiction to theoretical calculation, has led to speculation as to whether the magnetic ordering extends to the surface region. We use both static and time resolved ARPES to show that bulk magnetism does extend to the surface of MnBi2Te4. Our results have important implications for understanding the fundamental properties of the topological state and offer a clue for understanding its low quantum anomalous hall temperature.
D. Nevola et al. PRL 125, 117205, (2020).
D. Nevola et al. PRL 125, 117205, (2020).
*Work at BNL was supported by US Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DESC0012704. Funding at ORNL was supported by the US Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division. H.M. and R. G. M. were supported by the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory, managed by UT-Batelle, LLC for the US Department of Energy.
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Presenters
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Daniel Nevola
- Brookhaven National Laboratory
- North Carolina State University