Demonstration of Dissipative Quasihelical Edge Transport in Quantum Anomalous Hall Insulators

Doping a topological insulator (TI) film with transition metal ions can break its time-reversal symmetry and lead to the realization of the quantum anomalous Hall (QAH) effect. Prior studies have shown that the longitudinal resistance of the QAH samples usually does not vanish when the Hall resistance shows a good quantization. This has been interpreted as a result of the presence of possible dissipative conducting channels in magnetic TI samples. By studying the temperature- and magnetic-field-dependence of the magnetoresistance of a magnetic TI sandwich heterostructure device, we demonstrate that the predominant dissipation mechanism in thick QAH insulators can switch between nonchiral edge states and residual bulk states in different magnetic-field regimes. The interactions between bulk states, chiral edge states, and nonchiral edge states are also investigated. Our Letter provides a way to distinguish between the dissipation arising from the residual bulk states and nonchiral edge states, which is crucial for achieving true dissipationless transport in QAH insulators and for providing deeper insights into QAH-related phenomena.



Work Title Demonstration of Dissipative Quasihelical Edge Transport in Quantum Anomalous Hall Insulators
Open Access
  1. Shu-Wei Wang
  2. Di Xiao
  3. Ziwei Dou
  4. Moda Cao
  5. Yi-Fan Zhao
  6. Nitin Samarth
  7. Cui-Zu Chang
  8. Malcolm R. Connolly
  9. Charles G. Smith
License In Copyright (Rights Reserved)
Work Type Article
  1. American Physical Society (APS)
Publication Date September 18, 2020
Publisher Identifier (DOI)
  1. 10.1103/PhysRevLett.125.126801
  1. Physical Review Letters
Deposited September 09, 2021




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Work History

Version 1

  • Created
  • Added N Samarth- Demostration of Dissipative.pdf
  • Added Creator Shu-Wei Wang
  • Added Creator Di Xiao
  • Added Creator Ziwei Dou
  • Added Creator Moda Cao
  • Added Creator Yi-Fan Zhao
  • Added Creator Nitin Samarth
  • Added Creator Cui-Zu Chang
  • Added Creator Malcolm R. Connolly
  • Added Creator Charles G. Smith
  • Published
  • Updated
  • Updated