Wang Zhiyang, Chen Long-Qing
Department of Materials Science and Engineering, Materials Research Institute, The Pennsylvania State University, University Park, Pennsylvania 16802, United States.
Nano Lett. 2023 Nov 8;23(21):9907-9911. doi: 10.1021/acs.nanolett.3c02852. Epub 2023 Oct 26.
Polar skyrmions in oxide heterostructures have recently attracted extensive interest due to their unique physical properties and potential applications. Here, we report the formation of the vortex lattice and the nanoscale polar skyrmion crystals with two-dimensional hexagonal symmetry in PbTiO/SrTrO (PTO/STO) superlattices. Under an increasing external field, the system transitions from a vortex lattice phase to hexagonal polar skyrmion crystals (PSkC). The formation and annihilation process of the polar skyrmion crystals resemble the structural phase transition observed in atomic crystals. A temperature-electric field topological phase diagram is constructed, demonstrating stabilization of the vortex lattice and polar skyrmion crystals in a wide temperature and electric-field range. This study demonstrates the potential of manipulating the topological phase transition and its long-range order through an external field.
由于其独特的物理性质和潜在应用，氧化物异质结构中的极性斯格明子最近引起了广泛关注。在此，我们报道了在PbTiO/SrTrO（PTO/STO）超晶格中形成具有二维六方对称性的涡旋晶格和纳米级极性斯格明子晶体。在不断增加的外场作用下，系统从涡旋晶格相转变为六方极性斯格明子晶体（PSkC）。极性斯格明子晶体的形成和湮灭过程类似于在原子晶体中观察到的结构相变。构建了温度-电场拓扑相图，展示了涡旋晶格和极性斯格明子晶体在很宽的温度和电场范围内的稳定性。这项研究证明了通过外场操纵拓扑相变及其长程序的潜力。
