A fascinating aspect of nanoscale ferroelectric materials is the emergence of topological polar textures, which include various complex and stable polarization configurations. The manipulation of such topological textures through external stimuli like electric fields holds promise for advanced nanoelectronics applications. There are, however, several challenges to reach potential applications, among which reliably creating and controlling these textures at the nanoscale on silicon, and with lead-free compounds. We report the realization of epitaxial BaTiO₃ nanoislands on silicon, with a lateral size as small as 30-60 nm, and demonstrate stable center down-convergent polarization domains that can be reversibly switched by an electric field to center up-divergent domains. Piezoresponse force microscopy data reconstruction and phase field modeling give insight into the 3D patterns. The trapezoidal-shape nanoislands give rise to center down-convergent lateral swirling polarization component with respect to the nanoisland axis, which prevents the formation of bound charges on the side walls, therefore minimizing depolarization fields. The texture resembles a swirling vortex of liquid flowing into a narrowing funnel. Chirality emerges from the whirling polarization configurations. The ability to create and electrically manipulate chiral whirling polar textures in BaTiO₃ nanostructures grown monolithically on silicon holds promise for applications in future topological nanoelectronics.

纳米级铁电材料的一个迷人之处在于拓扑极性织构的出现，其中包括各种复杂而稳定的极化构型。通过电场等外部刺激操纵这种拓扑结构为先进的纳米电子应用带来了希望。然而，要实现潜在应用还存在一些挑战，其中包括在硅上可靠地创建和控制这些纳米级纹理，以及使用无铅化合物。我们报道了在硅上实现外延 BaTiO₃ 纳米岛，横向尺寸小至 30-60 nm，并展示了稳定的中心向下会聚极化畴，该畴可以通过电场可逆地切换到中心向上发散畴。压电响应力显微镜数据重建和相场建模可以深入了解 3D 模式。梯形纳米岛产生相对于纳米岛轴的中心向下收敛横向涡流极化分量，这可以防止在侧壁上形成束缚电荷，从而最大限度地减少去极化场。质地类似于流入狭窄漏斗的液体漩涡。手性从旋转的极化构型中出现。在硅上单片生长的 BaTiO₃ 纳米结构中创建和电操纵手性旋转极性纹理的能力为未来拓扑纳米电子学的应用带来了希望。