|DATE||September 19 (Wed), 2018|
|TITLE||Exotic topological phases induced by magnetic impurities in topological insulators|
Topological classification of matters has become a new way to comprehend emergent quantum phenomena in condensed matter physics ever since the discovery of the quantum Hall effect. Topological insulators (TIs), characterized by the coexistence of helical surface states and insulating bulk states, are widely used in combination with magnetic perturbations for explorations of innovative quantum states such as the quantum anomalous Hall effect (QAHE), large spin-orbit torque, Majorana fermion, giant exchange interaction, the topological magnetoelectric effect, and the quantized magneto-optical effect. In this talk, we especially discuss the magnetic ordering mechanism and the underlying physics behind the QAHE in magnetic doped TIs. We explain why the QAHE is observed at extremely low temperature (<100 mK) and propose a pragmatic way to improve the characteristic temperature. In addition, we also discuss a new way to induce the QAHE in TI thin films and examine the possibility of the realization of an axion insulator in TIs.