Polar Solomon Rings in Ferroelectric Nanocrystals

Abstract

Abstract Solomon rings, upholding the symbol of wisdom with profound historical roots, had been widely used as decoration in ancient architecture and clothes. Yet, it was only recently discovered that such topological structures can be formed by self-organization in biological/chemical molecules, liquid crystals, etc. Here, we report the observation of polar Solomon rings in a ferroelectric nanocrystal, which are composed of two interwoven vortices and mathematically equivalent to a 412 link in topology. By combining piezoresponse force microscopy observations and phase-field simulations, we demonstrate the reversible switching between polar Solomon rings and vertex textures by an electric field. The two types of topological polar textures exhibit distinct absorption of terahertz infrared waves, which can be utilized in infrared displays with a nanoscale resolution. Our study establishes, both experimentally and computationally, the existence and electric manipulation of polar Solomon rings, a new form of topological polar structures, which may provide a simple way for fast, robust, and high-resolution optoelectronic devices.