Distinct magnetic gaps between antiferromagnetic and ferromagnetic orders driven by surface defects in the topological magnet MnBi2Te4

Abstract

The magnetic topological insulator, MnBi${}_2$Te${}_4$, shows metallic behavior at zero magnetic fields (antiferromagnetic phase, AFM) in thin film transport, which coincides with gapless surface states observed by angle-resolved photoemission spectroscopy, while it can become a Chern insulator at field larger than 6 T (ferromagnetic phase, FM). Thus, the zero-field surface magnetism was once speculated to be different from the bulk AFM phase. However, recent magnetic force microscopy refutes this assumption by detecting persistent AFM order on the surface. In this work, we propose a mechanism related to surface defects that can rationalize these contradicting observations in different experiments. We find that co-antisites (exchanging Mn and Bi atoms in the surface van der Waals layer) can strongly suppress the magnetic gap down to several meV in the AFM phase without violating the magnetic order but preserve the magnetic gap in the FM phase. The different gap sizes between AFM and FM phases are caused by the defect-induced surface charge redistribution among top two van der Waals layers. This theory can be validated by the position- and field-dependent gap in future surface spectroscopy measurements. Our work suggests suppressing related defects in samples to realize the quantum anomalous Hall insulator or axion insulator at zero fields.

arXiv comment5 pages, 4 figures+1 table. Supplemental material is available

References in corpus (57)

• Experimental Observation of the Quantum Anomalous Hall Effect in a Magnetic Topological Insulator
• Magnetic-field-induced quantized anomalous Hall effect in intrinsic magnetic topological insulator MnBi${}_2$Te${}_4$
• Prediction and observation of the first antiferromagnetic topological insulator
• Intrinsic magnetic topological insulators in van der Waals layered MnBi${}_2$Te${}_4$-family materials
• Topological axion states in magnetic insulator MnBi${}_2$Te${}_4$ with the quantized magnetoelectric effect
• Robust axion insulator and Chern insulator phases in a two-dimensional antiferromagnetic topological insulator
• Experimental realization of an intrinsic magnetic topological insulator
• Unique thickness-dependent properties of the van der Waals interlayer antiferromagnet $\mathrm{MnB}{\mathrm{i}}_2\mathrm{T}{\mathrm{e}}_4$ films
• High-Chern-Number and High-Temperature Quantum Hall Effect without Landau Levels
• Realization of the Axion Insulator State in Quantum Anomalous Hall Sandwich Heterostructures
• Gapless surface Dirac cone in antiferromagnetic topological insulator MnBi${}_2$Te${}_4$
• Topological Electronic Structure and Its Temperature Evolution in Antiferromagnetic Topological Insulator MnBi2Te4
• Dirac surface states in intrinsic magnetic topological insulators EuSn2As2 and MnBi2nTe3n+1
• Spin scattering and noncollinear spin structure-induced intrinsic anomalous Hall effect in antiferromagnetic topological insulator $\mathrm{MnB}{\mathrm{i}}_2\mathrm{T}{\mathrm{e}}_4$
• A van der Waals antiferromagnetic topological insulator with weak interlayer magnetic coupling
• Natural van der Waals heterostructural single crystals with both magnetic and topological properties
• Axion Electrodynamics in Topological Materials
• Variety of magnetic topological phases in the (MnBi${}_2$Te${}_4$)(Bi${}_2$Te${}_3$)${}_m$ family
• Tailoring tricolor structure of magnetic topological insulator for robust axion insulator
• Gapless Dirac surface states in the antiferromagnetic topological insulator MnBi2Te4
• Realization of an intrinsic, ferromagnetic topological state in MnBi8Te13
• Intertwined Topological and Magnetic Orders in Atomically Thin Chern Insulator MnBi2Te4
• Observation of high-temperature quantum anomalous Hall regime in intrinsic MnBi${}_2$Te${}_4$/Bi${}_2$Te${}_3$ superlattice
• Topological electronic structure and intrinsic magnetization in MnBi${}_4$Te${}_7$: a Bi${}_2$Te${}_3$-derivative with a periodic Mn sublattice
• Mn-rich MnSb2Te4: A topological insulator with magnetic gap closing at high Curie temperatures of 45-50 K
• Site Mixing for Engineering Magnetic Topological Insulators
• Electronic states and magnetic response of MnBi2Te4 by scanning tunneling microscopy and spectroscopy
• Robust A-type order and spin-flop transition on the surface of the antiferromagnetic topological insulator MnBi${}_2$Te${}_4$
• Coexistence of Surface Ferromagnetism and Gapless Topological State in MnBi${}_2$Te${}_4$
• Defect-driven ferrimagnetism and hidden magnetization in MnBi${}_2$Te${}_4$
• Intrinsic axion insulating behavior in antiferromagnetic MnBi${}_6$Te${}_{10}$
• Magnetic topological insulator MnBi6Te10 with zero-field ferromagnetic state and gapped Dirac surface states
• Magnetic-field-induced robust zero Hall plateau state in MnBi${}_2$Te${}_4$ Chern insulator
• Half-Magnetic Topological Insulator
• Intrinsic magnetic topological insulators
• New interpretation of the origin of 2DEG states at the surface of layered topological insulators
• Sample-dependent Dirac point gap in MnBi${}_2$Te${}_4$ and its response to the applied surface charge: a combined photoemission and ab initio study
• Distinct Topological Surface States on the Two Terminations of MnBi${}_4$Te${}_7$
• Universal gapless Dirac cone and tunable topological states in (MnBi${}_2$Te${}_4$)${}_m$(Bi${}_2$Te${}_3$)${}_n$ heterostructures
• Electric control of a canted-antiferromagnetic Chern insulator
• Native Defects in Antiferromagnetic Topological Insulator MnBi${}_2$Te${}_4$
• Persistent gapless surface states in MnBi2Te4/Bi2Te3 superlattice antiferromagnetic topological insulator
• Magnetized Topological Insulator Multilayers
• Orbital Complexity in Intrinsic Magnetic Topological Insulators MnBi${}_4$Te${}_7$ and MnBi${}_6$Te${}_{10}$
• Analytical solution for the surface states of antiferromagnetic topological insulator MnBi${}_2$Te${}_4$
• Evidence for a magnetic-field induced ideal type-II Weyl state in antiferromagnetic topological insulator Mn(Bi1-xSbx)2Te4
• Tuning the magnetism and band topology through antisite defects in Sb doped MnBi4Te7
• Routes to realize the axion-insulator phase in MnBi${}_2$Te${}_4$(Bi${}_2$Te${}_3$)${}_n$ family: a perspective
• Coexisting of Quantum Hall and Quantum Anomalous Hall phases in Disordered $\mathrm{MnB}{\mathrm{i}}_2\mathrm{T}{\mathrm{e}}_4$
• Hybridization-Induced Gapped and Gapless States on the Surfaces of Magnetic Topological Insulators
• Visualizing the interplay of Dirac mass gap and magnetism at nanoscale in intrinsic magnetic topological insulators
• Light-Tunable Surface State and Hybridization Gap in Magnetic Topological Insulator MnBi${}_8$Te${}_{13}$
• Experimental evidence on the dissipationless transport of chiral edge state of the high-field Chern insulator in MnBi2Te4 nanodevices
• The elusive quantum anomalous Hall effect in MnBi2Te4: a materials perspective
• Ferromagnetic MnBi4Te7 obtained with low concentration Sb doping: A promising platform for exploring topological quantum states
• Detection of magnetic gap in the topological surface states of MnBi2Te4
• Facet dependent surface energy gap on magnetic topological insulators

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• On the topological surface states of the intrinsic magnetic topological insulator Mn-Bi-Te family
• Ubiquitous order-disorder transition in the Mn antisite sublattice of the (MnBi${}_2$Te${}_4$)(Bi${}_2$Te${}_3$)${}_n$ magnetic topological insulators
• Even-Odd Layer-Dependent Exchange Bias Effect in MnBi2Te4 Chern Insulator Devices
• Correlation between magnetic domain structures and quantum anomalous Hall effect in epitaxial MnBi2Te4 thin films
• Distinguishing Surface and Bulk Electromagnetism via Their Dynamics in an Intrinsic Magnetic Topological Insulator
• Intrinsic antiferromagnetic topological insulator and axion state in V2WS4
• Defect Engineering for Stabilizing Magnetic and Topological Properties in Mn(Bi1-xSbx)2Te4
• Reconstructing the wavefunction of magnetic topological insulators MnBi2Te4 and MnBi4Te7 using spin-resolved photoemission
• Strongly enhanced topological quantum phases in dual-surface AlO${}_x$-encapsulated MnBi${}_2$Te${}_4$
• Surface Reconstructions in Thin-Films of Magnetic Topological Insulator MnBi${}_2$Te${}_4$
• Fate of surface gaps in magnetic topological insulators
• Defect-induced displacement of topological surface state in quantum magnet MnBi${}_2$Te${}_4$
• Simple model for the gap in the surface states of the antiferromagnetic topological insulator MnBi${}_2$Te${}_4$