Observation of magnetism induced topological edge state in antiferromagnetic topological insulator MnBi4Te7

Abstract

Breaking time reversal symmetry in a topological insulator may lead to quantum anomalous Hall effect and axion insulator phase. MnBi4Te7 is a recently discovered antiferromagnetic topological insulator with TN ~12.5 K, which is constituted of alternatively stacked magnetic layer (MnBi2Te4) and non-magnetic layer (Bi2Te3). By means of scanning tunneling spectroscopy, we clearly observe the electronic state present at a step edge of a magnetic MnBi2Te4 layer but absent at non-magnetic Bi2Te3 layers at 4.5 K. Furthermore, we find that as the temperature rises above TN, the edge state vanishes, while the point defect induced state persists upon temperature increasing. These results confirm the observation of magnetism induced edge states. Our analysis based on an axion insulator theory reveals that the nontrivial topological nature of the observed edge state.

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Cited by in corpus (6)

• Dissipationless Layertronics in Axion Insulator $\mathrm{MnB}{\mathrm{i}}_2\mathrm{T}{\mathrm{e}}_4$
• Theory of the microwave impedance microscopy of Chern insulators
• Imaging the breakdown and restoration of topological protection in magnetic topological insulator MnBi${}_2$Te${}_4$
• Nonlinear Hall effect and scaling law in Sb-doped topological insulator MnBi4Te7
• Synthesis of intrinsic magnetic topological insulator MnBi2nTe3n+1 family by chemical vapor transport method with feedback regulation
• Topological properties of domain walls in antiferromagnetic topological insulators