Recent years have brought an explosion of activities in the research of topological aspects of condensed-matter systems. Topological phases of matter are accompanied by protected surface states or exotic degenerate excitations such as Majorana modes or Haldane’s localized spinons. Topologically protected degeneracies can, however, also appear in the bulk. An intriguing example is provided by Weyl semimetals, where topologically protected electronic band degeneracies and exotic surface states emerge even in the absence of interactions. Here we demonstrate experimentally and theoretically that Weyl degeneracies appear naturally in an interacting quantum dot system, for specific values of the external magnetic field. These magnetic Weyl points are robust against spin–orbit coupling unavoidably present in most quantum dot devices. Our transport experiments through an InAs double-dot device placed in magnetic field reveal the presence of a pair of Weyl points, exhibiting a robust ground-state degeneracy and a corresponding protected Kondo effect.

近年来，凝聚态系统拓扑方面的研究活动激增。物质的拓扑阶段伴随着受保护的表面状态或奇异的简并激发，例如马约拉那模式或霍尔丹的局限性自旋。但是，拓扑保护的简并性也可能会大量出现。Weyl半金属提供了一个引人入胜的示例，即使在没有相互作用的情况下，也出现了拓扑保护的电子带简并和奇特的表面态。在这里，我们通过实验和理论证明，对于外部磁场的特定值，Weyl简并自然出现在相互作用的量子点系统中。这些Weyl磁点对大多数量子点设备中不可避免地存在的自旋-轨道耦合具有鲁棒性。