The integration of diverse electronic phenomena, such as magnetism and nontrivial topology, into a single system is normally studied either by seeking materials that contain both ingredients, or by layered growth of contrasting materials1-9. The ability to simply stack very different two-dimensional van der Waals materials in intimate contact permits a different approach10,11. Here we use this approach to couple the helical edges states in a two-dimensional topological insulator, monolayer WTe2 (refs. 12-16), to a two-dimensional layered antiferromagnet, CrI3 (ref. 17). We find that the edge conductance is sensitive to the magnetization state of the CrI3, and the coupling can be understood in terms of an exchange field from the nearest and next-nearest CrI3 layers that produces a gap in the helical edge. We also find that the nonlinear edge conductance depends on the magnetization of the nearest CrI3 layer relative to the current direction. At low temperatures this produces an extraordinarily large nonreciprocal current that is switched by changing the antiferromagnetic state of the CrI3.

中文翻译：

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单层WTe2螺旋边缘中的磁性接近和不可逆电流切换。

通常，通过寻找包含两种成分的材料，或通过对比材料的分层生长1-9，来研究将各种电子现象（例如磁性和非平凡的拓扑结构）集成到单个系统中。简单地将非常不同的二维范德华材料紧密堆叠在一起的能力允许使用不同的方法10,11。在这里，我们使用这种方法将二维拓扑绝缘体单层WTe2（参考文献12-16）中的螺旋边缘状态耦合到二维分层反铁磁体CrI3（参考文献17）。我们发现边缘电导率对CrI3的磁化状态敏感，并且可以根据最近的和下一个最近的CrI3层的交换场来理解耦合，从而在螺旋边缘中产生间隙。我们还发现，非线性边缘电导取决于相对于电流方向最近的CrI3层的磁化强度。在低温下，这会产生非常大的不可逆电流，该电流通过改变CrI3的反铁磁状态进行切换。