The whorls of localized moments in chiral magnetic structures, such as skyrmions, lead to a quantized topological charge, which may make them useful as next-generation information bits. So far, the most reliable way to detect the existence of skyrmions is by using the topological Hall effect, which stems from electron scattering by the emergent magnetic field manifesting the topological charge. Here we employ two-dimensional magnets to establish a magneto-optical hallmark of skyrmions, which we call the topological Kerr effect, using the recently discovered ferromagnet CrVI₆ as a material platform. The Kerr angle hysteresis loop of this non-centrosymmetric system exhibits two antisymmetric bumps that are absent in the centrosymmetric CrI₃ and VI₃. We develop a minimal model to further identify the bumps as direct manifestations of the topological charge, thereby providing a magneto-optical fingerprint of skyrmions with broader applicability.

手性磁性结构（例如斯格明子）中的局部矩的螺旋会产生量子化的拓扑电荷，这可能使它们成为下一代信息位。到目前为止，检测斯格明子存在的最可靠方法是利用拓扑霍尔效应，该效应源于表现出拓扑电荷的涌现磁场的电子散射。在这里，我们使用最近发现的铁磁体 CrVI ₆作为材料平台，利用二维磁体建立了斯格明子的磁光特征，我们称之为拓扑克尔效应。该非中心对称系统的克尔角磁滞回线表现出中心对称 CrI ₃和 VI ₃中不存在的两个反对称凸起。我们开发了一个最小模型，以进一步将凸起识别为拓扑电荷的直接表现，从而提供具有更广泛适用性的斯格明子磁光指纹。