In magnetic topological insulators, quantized electronic transport is intertwined with spontaneous magnetic ordering, as magnetization controls band gaps, hence band topology, through the exchange interaction. We show that considering the exchange gaps at the mean-field level is inadequate to predict phase transitions between electronic states of distinct topology. Thermal spin fluctuations disturbing the magnetization can act as frozen disorders that strongly scatter electrons, reducing the onset temperature of quantized transport appreciably even in the absence of structural impurities. This effect, which has hitherto been overlooked, provides an alternative explanation of recent experiments on magnetic topological insulators.

中文翻译：

---

磁性拓扑绝缘子的定量输运中的自旋涨落

在磁性拓扑绝缘体中，量化的电子传输与自发的磁有序交织在一起，因为磁化通过交换相互作用控制带隙，从而控制带拓扑。我们表明，在平均场水平上考虑交换间隙不足以预测不同拓扑的电子状态之间的相变。扰动磁化的热自旋涨落可能会成为冻结的紊乱，使电子强烈散射，即使在没有结构性杂质的情况下，也明显降低了定量传输的起始温度。迄今为止，这种效应一直被忽视，它为磁拓扑绝缘子的最新实验提供了另一种解释。