Magnetic skyrmions are topologically stable swirling spin textures that appear as particle-like objects in two-dimensional (2D) systems. Here, utilizing scalar magnetic X-ray tomography under applied magnetic fields, we report the direct visualization of the three-dimensional (3D) shape of individual skyrmion strings in the room-temperature skyrmion-hosting non-centrosymmetric compound Mn_1.4Pt_0.9Pd_0.1Sn. Through the tomographic reconstruction of the 3D distribution of the [001] magnetization component on the basis of transmission images taken at various angles, we identify a skyrmion string running through the entire thickness of the sample, as well as various defect structures, such as the interrupted and Y-shaped strings. The observed point defect may represent the Bloch point serving as an emergent magnetic monopole, as proposed theoretically. Our tomographic approach with a tunable magnetic field paves the way for direct visualization of the structural dynamics of individual skyrmion strings in 3D space, which will contribute to a better understanding of the creation, annihilation and transfer of these topological objects.

磁性斯格明子是拓扑稳定的旋转自旋纹理，在二维 (2D) 系统中显示为类粒子物体。在这里，利用施加磁场下的标量磁 X 射线断层扫描，我们报告了室温 skyrmion 托管非中心对称化合物 Mn 1.4 Pt 0.9 Pd 0.1 中单个 skyrmion 串的三维 (3D)_形状的_直接可视_化锡。通过在不同角度拍摄的透射图像的基础上对 [001] 磁化分量的 3D 分布进行层析重建，我们识别出贯穿样品整个厚度的斯格明子串，以及各种缺陷结构，例如间断和 Y 形弦。观察到的点缺陷可能代表布洛赫点，如理论上所提出的那样，充当出射磁单极子。我们采用可调谐磁场的层析成像方法为在 3D 空间中直接可视化单个斯格明子串的结构动力学铺平了道路，这将有助于更好地理解这些拓扑物体的产生、湮灭和转移。