Hopfions emerge in ferroelectrics

• Published in: Nature communications 2020-05, Vol.11 (1), p.2433-2433, Article 2433
• Main Authors: Luk’yanchuk, I., Tikhonov, Y., Razumnaya, A., Vinokur, V. M.
• Format: Article
• Language: English
• Subjects: 639/766/119/2792/4129; 639/766/119/996; Astrophysics; Condensed matter physics; CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; Cosmology; Electromagnetic properties; Ferroelectric materials; Ferroelectricity; Ferroelectrics; Ferroelectrics and multiferroics; Fluid dynamics; Fluid flow; Humanities and Social Sciences; Hydrodynamics; multidisciplinary; Nanoparticles; Physical properties; Physics; Science; Science (multidisciplinary); Solitary waves; Topological defects; Topology
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-020-16258-w

Paradigmatic knotted solitons, Hopfions, that are characterized by topological Hopf invariant, attract an intense attention in the diverse areas of physics ranging from high-energy physics, cosmology and astrophysics to biology, magneto- and hydrodynamics and condensed matter physics. Yet, while being of broad interest, they remain elusive and under-explored. Here we demonstrate that Hopfions emerge as a basic configuration of polarization field in confined ferroelectric nanoparticles. Our findings establish that Hopfions are of fundamental importance for the electromagnetic behavior of the nanocomposits and can result in advanced functionalities of these materials. In spite of the growing recognition of the role of Hopfions in topological phases, their physical properties remain poorly understood. Here, the authors theoretically demonstrate that Hopfions are fundamental topological formations in confined ferroelectrics governing their electromagnetic response.