Journal Article

FZJ-2026-03980

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Defect-Induced Displacement of Topological Surface State in Quantum Magnet MnBi 2 Te 4

Lüpke, F.FZJ* ; Kolmer, M. ; Tan, H. ; Chang, H. ; Kaminski, A. ; Yan, B. ; Yan, J. ; Ko, W. ; Li, A.-P. (Corresponding author)

2026
APS College Park, Md.

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Please use a persistent id in citations: doi:10.1103/pt1j-996m  doi:10.34734/FZJ-2026-03980

Abstract: The topological magnet MnBi2⁢Te4(MBT), with gapped topological surface state, is an attractive platform for realizing quantum anomalous Hall and axion insulator states. However, the experimentally observed surface state gaps fail to meet theoretical predictions, although the exact mechanism behind the gap suppression has been debated. Recent theoretical studies suggest that intrinsic antisite defects push the topological surface state away from the MBT surface, closing its gap and making it less accessible to scanning probe experiments. Here, we report on the local effect of defects on the MBT surface states and demonstrate that high defect concentrations lead to a displacement of the surface states well into the MBT crystal, validating the theorized mechanism. The local and global influence of antisite defects on the topological surface states are studied with samples of varying defect densities by combining scanning tunneling microscopy, angle-resolved photoemission spectroscopy, and density functional theory. Our findings identify a combination of increased defect density and reduced defect spacing as the primary factors underlying the displacement of the surface states and suppression of surface gap, guiding further development of topological quantum materials.

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Contributing Institute(s):

1. Quantum Nanoscience (PGI-3)

Research Program(s):

1. 5213 - Quantum Nanoscience (POF4-521) (POF4-521)
2. DFG project G:(GEPRIS)511561801 - Manipulierung von 2D Supraleitung und Majorana Zuständen auf der Nanoskala (511561801) (511561801)

Appears in the scientific report 2026

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Database coverage:
; ; ; Clarivate Analytics Master Journal List ; Current Contents - Electronics and Telecommunications Collection ; Current Contents - Physical, Chemical and Earth Sciences ; Ebsco Academic Search ; Essential Science Indicators ; IF >= 5 ; JCR ; Nationallizenz ; SCOAP3 sponsored Journal ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

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