The topological nature of the quantum anomalous Hall effect (QAHE) causes a dissipationless chiral edge current at the sample boundary^1,2. Of fundamental interest is whether the chirality of the band structure manifests itself in charge transport properties. Here we report the observation of large non-reciprocal charge transport³ in a magnetic topological insulator, Cr-doped (Bi,Sb)₂Te₃. When the surface massive Dirac band is slightly carrier doped by a gate voltage, the edge state starts to dissipate and exhibits a current-direction-dependent resistance with a directional difference as large as 26%. The polarity of this diode effect depends on the magnetization direction as well as on the carrier type, electrons or holes. The correlation between the non-reciprocal resistance and the Hall resistance indicates that the non-reciprocity originates from the interplay between the chiral edge state and the Dirac surface state.

量子异常霍尔效应（QAHE）的拓扑性质在样品边界^1,2处引起无耗散手性边缘电流。基本感兴趣的是带结构的手性是否在电荷传输性质中表现出来。在这里，我们报告了在磁拓扑绝缘体Cr掺杂（Bi，Sb）₂ Te _3中的大不可逆电荷传输³的观察结果。。当表面块状狄拉克带由栅极电压稍微掺杂了载流子时，边缘状态开始耗散，并表现出与电流方向有关的电阻，其方向差高达26％。该二极管效应的极性取决于磁化方向以及载流子类型，电子或空穴。不可逆电阻与霍尔电阻之间的相关性表明，不可逆性源于手性边缘态与狄拉克表面态之间的相互作用。