Zhu Ruixue, Jiang Zhexin, Zhang Xinxin, Zhong Xiangli, Tan Congbing, Liu Mingwei, Sun Yuanwei, Li Xiaomei, Qi Ruishi, Qu Ke, Liu Zhetong, Wu Mei, Li Mingqiang, Huang Boyuan, Xu Zhi, Wang Jinbin, Liu Kaihui, Gao Peng, Wang Jie, Li Jiangyu, Bai Xuedong
Electron Microscopy Laboratory and International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China.
Department of Engineering Mechanics, Zhejiang University, Hangzhou 310027, Zhejiang, China.
Phys Rev Lett. 2022 Sep 2;129(10):107601. doi: 10.1103/PhysRevLett.129.107601.
Room-temperature polar skyrmions, which have been recently discovered in oxide superlattice, have received considerable attention for their potential applications in nanoelectronics owing to their nanometer size, emergent chirality, and negative capacitance. For practical applications, their manipulation using external stimuli is a prerequisite. Herein, we study the dynamics of individual polar skyrmions at the nanoscale via in situ scanning transmission electron microscopy. By monitoring the electric-field-driven creation, annihilation, shrinkage, and expansion of topological structures in real space, we demonstrate the reversible transformation among skyrmion bubbles, elongated skyrmions, and monodomains. The underlying mechanism and interactions are discussed in conjunction with phase-field simulations. The electrical manipulation of nanoscale polar skyrmions allows the tuning of their dielectric permittivity at the atomic scale, and the detailed knowledge of their phase transition behaviors provides fundamentals for their applications in nanoelectronics.
室温极性斯格明子最近在氧化物超晶格中被发现，由于其纳米尺寸、新兴手性和负电容，在纳米电子学中的潜在应用受到了广泛关注。对于实际应用而言，利用外部刺激对其进行操控是一个先决条件。在此，我们通过原位扫描透射电子显微镜研究了纳米尺度下单个极性斯格明子的动力学。通过在实空间中监测电场驱动的拓扑结构的产生、湮灭、收缩和扩展，我们展示了斯格明子气泡、拉长的斯格明子和单畴之间的可逆转变。结合相场模拟讨论了其潜在机制和相互作用。纳米尺度极性斯格明子的电操控使得在原子尺度上调节其介电常数成为可能，而对其相变行为的详细了解为它们在纳米电子学中的应用提供了基础。
