Direct switching of polarization vortex in triangular ferroelectric nanodots: Role of crystal orientation

Attaining an energy-efficient pathway to switch the rotation of polarization vortex with the use of trivial homogeneous electric field is essentially important for low-power consumption electronic nanodevices, yet still challenging. In this study, we systematically investigate the switching behaviors of polarization vortex in triangular ferroelectric nanodots with different crystal orientations. The obtained results exhibit diversity pathways for the vortex switching, including both indirect and direct switching, which depend on the crystal orientation. In the indirect pathway, the switching process requires a destruction of initial vortex domain structure to form a rectilinear domain at a large electric field. Otherwise, in the direct switching pathway, the initial vortex is switched to an opposite one without the stabilization of an intermediate state. Importantly, the direct pathway requires a lower switching field compared to that in the indirect ones. We further elucidate the temporal evolution of domain structure during the direct switching of polarization vortex in the triangular nanodot. A comprehensive viewpoint on the effect of crystal orientation is expressed, from which the advantages of direct switching are clarified. The present study suggests an efficient route on the practical control of vortex rotation in ferroelectric nanostructures under homogeneous electric field.