Current-driven instability of quantum anomalous Hall effect in ferromagnetic topological insulators

Abstract

Instability of quantum anomalous Hall (QAH) effect has been studied as function of electric current and temperature in ferromagnetic topological insulator thin films. We find that a characteristic current for the breakdown of the QAH effect is roughly proportional to the Hall-bar width, indicating that Hall electric field is relevant to the breakdown. We also find that electron transport is dominated by variable range hopping (VRH) at low temperatures. Combining the current and temperature dependences of the conductivity in the VRH regime, the localization length of the QAH state is evaluated to be about 5 $\mu$m. The long localization length suggests a marginally insulating nature of the QAH state due to a large number of in-gap states.

5 pages, 4 figures, accepted for publication in PRL

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Cited by in corpus (2)

• Demonstration of Dissipative Quasihelical Edge Transport in Quantum Anomalous Hall Insulators
• Current scaling of the topological quantum phase transition between a quantum anomalous Hall insulator and a trivial insulator