Realizing applicably appreciated spintronic functionalities basing on the coupling between charge and spin degrees of freedom is still a challenge. For example, the anisotropic magnetoresistance (AMR) effect can be utilized to read out the information stored in magnetic structures. However, the application of AMR in antiferromagnet-based spintronics is usually hindered by the small AMR value. Here, we discover a colossal AMR with its value reaching 1.84 × 10⁶% at 2 K, which stems from the field-induced metal-to-insulator transition (MIT), in a nearly Dirac material EuMnSb₂. Density functional theory calculations identify a Dirac-like band around the Y point that depends strongly on the spin–orbit coupling and dominates the electrical transport. The indirect band gap at the Fermi level evolves with magnetic structure of Eu²⁺ moments, consequently giving rise to the field-induced MIT and the colossal AMR. Our results suggest that the antiferromagnetic topological materials can serve as a fertile ground for spintronics applications.

基于电荷和自旋自由度之间的耦合实现可应用的自旋电子功能仍然是一个挑战。例如，可以利用各向异性磁阻 (AMR) 效应读出存储在磁结构中的信息。然而，AMR 在基于反铁磁体的自旋电子学中的应用通常受到 AMR 值小的阻碍。在这里，我们发现了一个巨大的 AMR，其值在 2 K 时达到 1.84 × 10 ⁶ %，这源于场致金属到绝缘体的转变 (MIT)，在接近狄拉克的材料 EuMnSb _{2 中}。密度泛函理论计算确定了Y周围的类狄拉克带强烈依赖于自旋轨道耦合并主导电传输的点。费米能级的间接带隙随着 Eu ²⁺矩的磁结构演变，从而产生场致 MIT 和巨大的 AMR。我们的结果表明，反铁磁拓扑材料可以作为自旋电子学应用的沃土。