论文标题
轴承绝缘子薄膜中的动力磁电耦合
Dynamical magnetoelectric coupling in axion insulator thin films
论文作者
论文摘要
Axion绝缘子是一种外来的磁性绝缘子，其零零数为零，但非零量化的Chern-Simons磁电耦合。由于拓扑磁电效应（TME）的小信号，仍缺乏轴突绝缘子的最终实验证据。在这里，我们表明，动态磁电耦合可以通过轴轴测绝缘子薄膜中的\ emph {平面外}表面磁化动力学诱导，该膜在同一方向上存在外部磁场的情况下进一步生成极化电流。这样的电流在批量上是有限的，并且随着膜厚度$ d $的减小而增加，与TME电流相反，随着$ d $的降低，这种电流会减少。值得注意的是，磁共振上的薄膜中的电流至少比TME大十倍，因此可以用作轴突绝缘子的吸烟枪标志。
Axion insulator is an exotic magnetic topological insulator with zero Chern number but a nonzero quantized Chern-Simons magnetoelectric coupling. A conclusive experimental evidence for axion insulators is still lacking due to the small signal of topological magnetoelectric effect (TME). Here we show that the dynamical magnetoelectric coupling can be induced by the \emph{out-of-plane} surface magnetization dynamics in axion insulator thin films, which further generates a polarization current in the presence of an external magnetic field in the same direction. Such a current is finite in the bulk and increases as the film thickness $d$ decreases, in opposite to TME current which decreases as $d$ decreases. Remarkably, the current in thin films at magnetic resonance is at least ten times larger than that of TME, and thus may serve as a smoking gun signature for axion insulators.
