"Observation of the Zero Hall Plateau in a Quantum Anomalous Hall Insulator"

Yang Feng: Xiao Feng, Yunbo Ou, Jing Wang, Chang Liu, Liguo Zhang, Dongyang Zhao, Gaoyuan Jiang, Shou-Cheng Zhang, Ke He, Xucun Ma, Qi-Kun Xue, and Yayu Wang; Physical Review Letters, 09/16/15.

Additional Authors: Xiao Feng, Yunbo Ou, Jing Wang, Chang Liu, Liguo Zhang, Dongyang Zhao, Gaoyuan Jiang, Shou-Cheng Zhang, Ke He, Xucun Ma, Qi-Kun Xue, and Yayu Wang

Abstract:

We report experimental investigations on the quantum phase transition between the two opposite Hall plateaus of a quantum anomalous Hall insulator. We observe a well-defined plateau with zero Hall conductivity over a range of magnetic field around coercivity when the magnetization reverses. The features of the zero Hall plateau are shown to be closely related to that of the quantum anomalous Hall effect, but its temperature evolution exhibits a significant difference from the network model for a conventional quantum Hall plateau transition. We propose that the chiral edge states residing at the magnetic domain boundaries, which are unique to a quantum anomalous Hall insulator, are responsible for the novel features of the zero Hall plateau.