Figure 1: Quantum anomalous Hall effect in the six QL (Cr_0.12Bi_0.26Sb_0.62)₂Te₃ film.

(a) Schematic representation of the mm-sized Hall bar structure and four-point Hall measurements based on the MBE-grown magnetic TI thin film. (b) Quantum anomalous Hall results at T=0.26 K. The Hall resistances are quantized to be±h/e² where the signs are determined by the chirality of the edge conduction. (c) Temperature-dependent magneto-resistance results (from 0.02 to 13 K). At the coercive field, the peak of R_xx quickly diverges at lower temperatures. (d)Temperature-dependent R_{xx_PEAK} and R_yx extracted from (b,c). The anomalous Hall resistance R_yx becomes quantized up to 0.3 K, and the giant R_{xx_PEAK} resolved at 0.02 K is ∼400 kΩ, the largest value obtained among all reported QAHE systems.