Topological domain structures have drawn great attention as they have potential applications in future electronic devices. As an important concept linking the quantum and classical magnetism, a magnetic Bloch point, predicted in 1960s but not observed directly so far, is a singular point around which magnetization vectors orient to nearly all directions. Here we show polar Bloch points in tensile-strained ultrathin ferroelectric PbTiO₃ films, which are alternatively visualized by phase-field simulations and aberration-corrected scanning transmission electron microscopic imaging. The phase-field simulations indicate local steady-state negative capacitance around the Bloch points. The observation of polar Bloch points and their emergent properties consequently implies novel applications in future integrated circuits and low power electronic devices.

拓扑域结构因其在未来电子设备中的潜在应用而引起了极大的关注。作为连接量子和经典磁学的重要概念，磁布洛赫点是一个奇点，磁化矢量围绕该奇点几乎指向所有方向，该奇点于 20 世纪 60 年代被预测，但迄今为止尚未直接观测到。在这里，我们展示了拉伸应变超薄铁电 PbTiO ₃薄膜中的极布洛赫点，这些点可以通过相场模拟和像差校正扫描透射电子显微成像来可视化。相场模拟表明布洛赫点周围存在局部稳态负电容。因此，对极布洛赫点及其涌现特性的观察意味着未来集成电路和低功率电子设备中的新应用。