Polar Bloch points in strained ferroelectric films
Yujia Wang, Yanpeng Feng, Yun‐Long Tang, Yin‐Lian Zhu, Yi Cao, Min-Jie Zou, Wan‐Rong Geng, Xiuliang Ma
Abstract
Abstract 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 PbTiO 3 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.