Effects of Random Domains on the Zero Hall Plateau in the Quantum Anomalous Hall Effect

Abstract

Recently, a zero Hall conductance plateau with random domains is experimentally observed in quantum anomalous Hall (QAH) effect. We study the effects of random domains on the zero Hall plateau in QAH insulators. We find the structure inversion symmetry determines the scaling property of the zero Hall plateau transition in the QAH systems. In the presence of structure inversion symmetry, the zero Hall plateau state shows a quantum-Hall-type critical point, originating from the two decoupled subsystems with opposite Chern numbers. However, the absence of structure inversion symmetry leads to mixture between these two subsystems, gives rise to a line of critical points, and dramatically changes the scaling behavior. Hereinto, we predict a Berezinskii-Kosterlitz-Thouless-type transition during the Hall conductance plateau switching in the QAH insulators. Our results are instructive for both theoretic understanding of the zero Hall plateau transition and future transport experiments in the QAH insulators.

Scaling behavior of the quantum phase transition from a quantum-anomalous-Hall insulator to an axion insulator

“…In our samples, as the density of states of Dirac fermions is low, the long-range Coulomb interaction is unscreened and the triplet interaction channel is eliminated due to the strong spin-orbital coupling of TI materials 32 . We note that the QAH to axion insulator transition in magnetic TI sandwiches belongs to the QH-type instead of the Berezinskii-Kosterlitz-Thouless-type transition as we predicted in an individual magnetic TI thin film with random domains 37 . In such an individual magnetic TI thin film, the top and bottom surfaces are coupled and play a joint role, so this case is described by the Chalker-Coddington model with two channels 37,38 .…”

“…We note that the QAH to axion insulator transition in magnetic TI sandwiches belongs to the QH-type instead of the Berezinskii-Kosterlitz-Thouless-type transition as we predicted in an individual magnetic TI thin film with random domains 37 . In such an individual magnetic TI thin film, the top and bottom surfaces are coupled and play a joint role, so this case is described by the Chalker-Coddington model with two channels 37,38 . In other words, the magnetization reversal during the QAH plateauto-plateau transition occurs on both the top and bottom surfaces.…”

Magnetic resonance induced pseudoelectric field and giant current response in axion insulators

“…1(a), leading to the zero Hall plateau of the AI phase. However, zero Hall plateau may also occur in a trivial or Anderson insulator [32][33][34][35]. In contrast, for an in-plane electric field with opposite directions at two surfaces, the Hall current is expected to be non-zero in the AI phase ( Fig.…”

Evolution of Berry curvature and reentrant quantum anomalous Hall effect in an intrinsic magnetic topological insulator

“…Meanwhile, the QAH state was also observed the oddnumber septuple-layered MnBi 2 Te 4 , but the quantization of Hall resistance strongly depends on disorder and external magnetic field [27]. This implies that disorder and magnetization [28][29][30][31][32][33] are two key ingredients to determine and manipulate the QAH effect in this intrinsic magnetic TI material. Moreover, the QAH state in magnetic field-driven FM ordered MnBi 2 Te 4 usually occurs at a high magnetic field [25,26], which raises the concerns on the possible realization of Landau levels.…”