The quantum Hall effect (QHE), a quantized version of the Hall effect [1], was observed in two-dimensional (2D) electron systems under magnetic field more than 40 years ago [2, 3]. The quantum anomalous Hall (QAH) effect refers to a quantized version of the anomalous Hall effect [4], which doesn’t require an external magnetic field. It had been predicted to occur in “2D graphite” with broken time reversal invariance [5], and more recently in 2D magnetic topological insulators [6, 7]. It was first experimentally observed in thin films of magnetically doped (Bi,Sb)2Te3 topological insulator in 2013 [8]. In this talk, the history and recent progress in the study of QAH effect are presented.

References
[1] E. H. Hall, Am. J. Math. 2, 287 (1879).
[2] K. von Klitzing, G. Dorda, M. Pepper, Phys. Rev. Lett. 45, 494 (1980).
[3] D. C. Tsui, H. L. Stormer, A. C. Gossard, Phys. Rev. Lett. 48, 1559 (1982).
[4] E. H. Hall, Philos. Mag. 12, 157 (1881).
[5] F. D. M. Haldane, Phys. Rev. Lett. 61, 2015 (1988).
[6] M. Z. Hasan, C. L. Kane, Rev. Mod. Phys. 82, 3045 (2010).
[7] X. L. Qi, S. C. Zhang, Rev. Mod. Phys. 83, 1057 (2011).
[8] C. Z. Chang et al., Science 340, 167 (2013).