1. Helical Luttinger Liquid on the Edge of a Two-Dimensional Topological Antiferromagnet
- Author
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Feng, Yang, Zhu, Jinjiang, Lin, Weiyan, Lian, Zichen, Wang, Yongchao, Li, Hao, Yao, Hongxu, He, Qiushi, Pan, Yinping, Wu, Yang, Zhang, Jinsong, Wang, Yayu, Zhou, Xiaodong, Shen, Jian, and Wang, Yihua
- Abstract
A boundary helical Luttinger liquid (HLL) with broken bulk time-reversal symmetry belongs to a unique topological class that may occur in antiferromagnets (AFM). Here, we search for signatures of HLL on the edge of a recently discovered topological AFM, MnBi2Te4even-layer. Using a scanning superconducting quantum interference device, we directly image helical edge current in the AFM ground state appearing at its charge neutral point. Such a helical edge state accompanies an insulating bulk which is topologically distinct from the ferromagnetic Chern insulator phase, as revealed in a magnetic field driven quantum phase transition. The edge conductance of the AFM order follows a power law as a function of temperature and source-drain bias which serves as strong evidence for HLL. Such HLL scaling is robust at finite fields below the quantum critical point. The observed HLL in a layered AFM semiconductor represents a highly tunable topological matter compatible with future spintronics and quantum computation.
- Published
- 2022
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