Interface-Engineered Polar Topological Domains in Ferroelectric Nematic Liquid Crystals.

Abstract

Polar topological domains, distinguished by their inherent topological protection and diverse optoelectronic functionalities, have recently attracted significant interest across scientific disciplines. However, the realization of these structures in inorganic materials is often impeded by crystal symmetry constraints. In this context, ferroelectric nematic liquid crystals, characterized by spontaneous polarization and flexible polarization orientation, provide an exceptional platform for the development of polar topological domains. Despite their potential, a considerable challenge lies in identifying a straightforward yet versatile approach for engineering polar topological domains within liquid crystals. Here, this study presents an interfacial engineering strategy that effectively stabilizes a range of polar topological domains in ferroelectric nematic liquid crystals, including vortex, centrifugal vortex, and center-divergent configurations, by synergistically modulating the surface tension and interfacial tension. Utilizing a combination of experimental characterization and simulation, the role of anchoring energy is systematically investigated in the molecular alignment of liquid crystals and facilitates transitions between diverse topological structures. This research not only extends the horizons for constructing and manipulating polar topological domains but also enhances their prospective applications in topological photonics.