Creating topological polar structure in a nonpolar matter

TL;DR

This paper demonstrates the creation of atomic-scale polar antivortices in nonpolar SrTiO3, expanding the understanding and potential applications of topological polar structures beyond ferroelectric materials.

Contribution

It introduces a novel method to create polar topologies in nonpolar materials, specifically antivortices in SrTiO3, which was previously unachievable.

Findings

Atomic-scale polar antivortices successfully created in SrTiO3.

Expands the scope of topological polar structures beyond ferroelectric materials.

Provides new insights into the formation mechanisms of polar topologies.

Abstract

Nontrivial topological structures offer rich playground in condensed matter physics including fluid dynamics, superconductivity, and ferromagnetism, and they promise alternative device configurations for post-Moore spintronics and electronics. Indeed, magnetic skyrmions are actively pursued for high-density data storage, while polar vortices with exotic negative capacitance may enable ultralow power consumption in microelectronics. Following extensive investigations on a variety of magnetic textures including vortices, domain walls and skyrmions in the past decades, studies on polar topologies have taken off in recent years, resulting in discoveries of closure domains, vortices, and skyrmions in ferroelectric materials. Nevertheless, the atomic-scale creation of topological polar structures is largely confined in a single ferroelectric system, PbTiO3 (PTO) with large polarization, casting doubt on the generality of polar topologies and limiting their potential applications. In this work, we successfully create previously unrealized atomic-scale polar antivortices in the nominally nonpolar SrTiO3 (STO), expanding the reaches of topological structures and completing an important missing link in polar topologies. The work shed considerable new insight into the formation of topological polar structures, and offers guidance in searching for new polar textures.