High quality chromium （Cr） doped three-dimensional topological insulator （TI） Sb2Te3 films are grown via molecular beam epitaxy on heat-treated insulating SrTiO3 （111） substrates. We report that the Dirac surfac...High quality chromium （Cr） doped three-dimensional topological insulator （TI） Sb2Te3 films are grown via molecular beam epitaxy on heat-treated insulating SrTiO3 （111） substrates. We report that the Dirac surface states are insensitive to Cr doping, and a perfect robust long-range ferromagnetic order is unveiled in epitaxial Sb2 xCrxTe3 films. The anomalous Hall effect is modulated by applying a bottom gate, contrary to the ferromagnetism in conventional diluted magnetic semiconductors （DMSs）, here the coercivity field is not significantly changed with decreasing cartier density. Carrier-independent ferromag- netism heralds Sbz_xCrxTe3 films as the base candidate TI material to realize the quantum anomalous Hall （QAH） effect. These results also indicate the potential of controlling anomalous Hall voltage in future TI-based magneto-electronics and spintronics.展开更多
基金the National Natural Science Foundation of China(Grant No.11174343)the Ministry of Science and Technology of Chinathe Chinese Academy of Sciences
文摘High quality chromium （Cr） doped three-dimensional topological insulator （TI） Sb2Te3 films are grown via molecular beam epitaxy on heat-treated insulating SrTiO3 （111） substrates. We report that the Dirac surface states are insensitive to Cr doping, and a perfect robust long-range ferromagnetic order is unveiled in epitaxial Sb2 xCrxTe3 films. The anomalous Hall effect is modulated by applying a bottom gate, contrary to the ferromagnetism in conventional diluted magnetic semiconductors （DMSs）, here the coercivity field is not significantly changed with decreasing cartier density. Carrier-independent ferromag- netism heralds Sbz_xCrxTe3 films as the base candidate TI material to realize the quantum anomalous Hall （QAH） effect. These results also indicate the potential of controlling anomalous Hall voltage in future TI-based magneto-electronics and spintronics.
