Field-effect modulation of anomalous Hall effect in diluted ferromagnetic topological insulator epitaxial films

• Published in: Science China. Physics, mechanics & astronomy Vol. 59; no. 3; pp. 100 - 104
• Main Authors: Chang, CuiZu, Liu, MinHao, Zhang, ZuoCheng, Wang, YaYu, He, Ke, Xue, QiKun
• Format: Journal Article
• Language: English
• Published: Beijing Science China Press 01.03.2016; Springer Nature B.V
• Subjects: Astronomy; Carrier density; Chromium; Classical and Continuum Physics; Coercivity; Cr掺杂; Dilution; Epitaxial growth; Ferromagnetic materials; Hall effect; Heat treatment; Magnetic semiconductors; Molecular beam epitaxy; Observations and Techniques; Physics; Physics and Astronomy; Spintronics; SrTiO3; Substrates; Topological insulators; 三维拓扑; 反常霍尔效应; 场效应; 外延膜; 绝缘体; 调制; carrier-independent ferromagnetism; topological insulators (TIs); electrical field-effect; anomalous Hall (QAH) effect
• ISSN: 1674-7348; 1869-1927
• DOI: 10.1007/s11433-015-5761-9

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.