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Confinement-Induced Chiral Edge Channel Interaction in Quantum Anomalous Hall Insulators

Authors :
Zhou, Ling-Jie
Mei, Ruobing
Zhao, Yi-Fan
Zhang, Ruoxi
Zhuo, Deyi
Yan, Zi-Jie
Yuan, Wei
Kayyalha, Morteza
Chan, Moses H. W.
Liu, Chao-Xing
Chang, Cui-Zu
Source :
Phys. Rev. Lett. 130, 086201(2023)
Publication Year :
2022

Abstract

In quantum anomalous Hall (QAH) insulators, the interior is insulating but electrons can travel with zero resistance along one-dimensional conducting paths known as chiral edge channels (CECs). These CECs have been predicted to be confined to the one-dimensional (1D) edges and exponentially decay in the two-dimensional (2D) bulk. In this work, we present the results of a systematic study of QAH devices fashioned in a Hall bar geometry of different widths. At the charge neutral point, the QAH effect persists in a Hall bar device with a width of only ~72 nm, implying the intrinsic decaying length of CECs is less than ~36 nm. In the electron-doped regime, we find that the Hall resistance deviates quickly from the quantized value when the sample width is less than 1 um. Our theoretical calculations suggest that the deviation from the quantized Hall resistance in narrow QAH samples originates from the interaction between two opposite CECs mediated by disorder-induced bulk states in QAH insulators, consistent with our experimental observations.<br />Comment: 19 pages, 5 figures, comments are welcome

Details

Database :
arXiv
Journal :
Phys. Rev. Lett. 130, 086201(2023)
Publication Type :
Report
Accession number :
edsarx.2207.08371
Document Type :
Working Paper
Full Text :
https://doi.org/10.1103/PhysRevLett.130.086201