Nontrivial topology in condensed-matter systems enriches quantum states of matter to go beyond either the classification into metals and insulators in terms of conventional band theory or that of symmetry-broken phases by Landau’s order parameter framework. So far, focus has been on weakly interacting systems, and little is known about the limit of strong electron correlations. Heavy fermion systems are a highly versatile platform to explore this regime. Here we report the discovery of a giant spontaneous Hall effect in the Kondo semimetal Ce3Bi4Pd3 that is noncentrosymmetric but preserves time-reversal symmetry. We attribute this finding to Weyl nodes—singularities of the Berry curvature—that emerge in the immediate vicinity of the Fermi level due to the Kondo interaction. We stress that this phenomenon is distinct from the previously detected anomalous Hall effect in materials with broken time-reversal symmetry; instead, it manifests an extreme topological response that requires a beyond-perturbation-theory description of the previously proposed nonlinear Hall effect. The large magnitude of the effect in even tiny electric and zero magnetic fields as well as its robust bulk nature may aid the exploitation in topological quantum devices.

凝聚态系统中的非平凡拓扑结构丰富了物质的量子态，从而超越了传统能带理论或朗道阶数参数框架所定义的对称破碎相的范畴。到目前为止，焦点一直集中在弱相互作用的系统上，关于强电子相关性的极限知之甚少。重型费米子系统是探索这种状态的多功能平台。在这里，我们报告在近藤半金属中发现了巨大的自发霍尔效应CË3乙一世4Pd3这是非中心对称的，但保留了时间反转对称性。我们将这一发现归因于由于近藤相互作用而在费米能级附近产生的Weyl节点（浆果曲率的奇异点）。我们强调，这种现象不同于先前发现的具有逆时对称性的材料中的异常霍尔效应。相反，它表现出一种极端的拓扑响应，需要对先前提出的非线性霍尔效应进行超扰动理论描述。即使在很小的电场和零磁场中，其巨大的影响力及其强大的整体性质也可能有助于拓扑量子器件的开发。