Orbital Complexity in Intrinsic Magnetic Topological Insulators MnBi_{4}Te_{7} and MnBi_{6}Te_{10}
R C Vidal1,2, H Bentmann1,2, J I Facio3
1Experimentelle Physik VII, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany, EU.
Physical Review Letters
|May 14, 2021
Summary
Magnetic topological insulators MnBi4Te7 and MnBi6Te10 exhibit complex surface electronic structures. Surface termination dictates whether topological surface states are preserved, crucial for quantized anomalous Hall conductivity.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Phenomena
Background:
- Magnetic van der Waals compounds are promising for novel electronic applications.
- Intrinsic magnetic topological insulators offer unique quantum properties.
- MnBi4Te7 and MnBi6Te10 belong to a series with potential topological and magnetic functionalities.
Purpose of the Study:
- To investigate the surface electronic structure of MnBi4Te7 and MnBi6Te10.
- To understand the interplay between magnetism, topology, and surface termination.
- To determine the conditions for preserving topological surface states.
Main Methods:
- Angle-resolved photoelectron spectroscopy (ARPES) with circular dichroic, spin-resolved, and photon-energy-dependent measurements.
- Density functional theory (DFT) calculations.
- Characterization of surface electronic band structure and spin textures.
Main Results:
- Unveiled complex momentum-dependent orbital and spin textures in the surface electronic structure.
- Disentangled topological from trivial surface bands.
- Observed strong perturbation of Dirac-cone dispersion by hybridization on Bi2Te3-terminated surfaces.
- Found preserved Dirac-cone dispersion on MnBi2Te4-terminated surfaces.
Conclusions:
- Established the topologically nontrivial nature of MnBi4Te7 and MnBi6Te10.
- Demonstrated that surface termination critically influences the preservation of topological surface states.
- Indicated that quantized anomalous Hall conductivity realization is dependent on specific surface terminations.
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