Scale-Invariant Dissipationless Chiral Transport in Magnetic Topological Insulators beyond the Two-Dimensional Limit

摘要

We investigate the quantum anomalous Hall Effect (QAHE) and related chiraltransport in the millimeter-size (Cr0.12Bi0.26Sb0.62)2Te3 films. With highsample quality and robust magnetism at low temperatures, the quantized Hallconductance of e2/h is found to persist even when the film thickness is beyondthe two-dimensional (2D) hybridization limit. Meanwhile, the Cherninsulator-featured chiral edge conduction is manifested by the non-localtransport measurements. In contrast to the 2D hybridized thin film, anadditional weakly field-dependent longitudinal resistance is observed in the 10quintuple-layer film, suggesting the influence of the film thickness on thedissipative edge channel in the QAHE regime. The extension of QAHE into thethree-dimensional thickness region addresses the universality of this quantumtransport phenomenon and motivates the exploration of new QAHE phases withtunable Chern numbers. In addition, the observation of the scale-invariantdissipationless chiral propagation on a macroscopic scale makes a major stridetowards ideal low-power interconnect applications.