Beijing National Laboratory for Condensed Matter Physics, and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
Science. 2010 Jul 2;329(5987):61-4. doi: 10.1126/science.1187485. Epub 2010 Jun 3.
The anomalous Hall effect is a fundamental transport process in solids arising from the spin-orbit coupling. In a quantum anomalous Hall insulator, spontaneous magnetic moments and spin-orbit coupling combine to give rise to a topologically nontrivial electronic structure, leading to the quantized Hall effect without an external magnetic field. Based on first-principles calculations, we predict that the tetradymite semiconductors Bi2Te3, Bi2Se3, and Sb2Te3 form magnetically ordered insulators when doped with transition metal elements (Cr or Fe), in contrast to conventional dilute magnetic semiconductors where free carriers are necessary to mediate the magnetic coupling. In two-dimensional thin films, this magnetic order gives rise to a topological electronic structure characterized by a finite Chern number, with the Hall conductance quantized in units of e2/h (where e is the charge of an electron and h is Planck's constant).
反常霍尔效应是固体中一种源于自旋轨道耦合的基本输运过程。在量子反常霍尔绝缘体中，自发磁矩和自旋轨道耦合相结合，导致拓扑非平凡的电子结构，从而在没有外磁场的情况下产生量子霍尔效应。基于第一性原理计算，我们预测碲化铋、碲化硒和碲化锑等四碲化物半导体在掺杂过渡金属元素（Cr 或 Fe）时会形成磁性有序绝缘体，而在传统的稀磁半导体中，需要自由载流子来介导磁耦合。在二维薄膜中，这种磁有序导致具有有限陈数的拓扑电子结构，其中霍尔电导以 e2/h 的单位量子化（其中 e 是电子的电荷，h 是普朗克常数）。
