ABSTRACT
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.
ABSTRACT
Chirality, an intrinsic handedness, is one of the most intriguing fundamental phenomena in nature. Materials composed of chiral molecules find broad applications in areas ranging from nonlinear optics and spintronics to biology and pharmaceuticals. However, chirality is usually an invariable inherent property of a given material that cannot be easily changed at will. Here, we demonstrate that ferroelectric nanodots support skyrmions the chirality of which can be controlled and switched. We devise protocols for realizing control and efficient manipulations of the different types of skyrmions. Our findings open the route for controlled chirality with potential applications in ferroelectric-based information technologies.
ABSTRACT
We studied the influence of the induced strain and applied electric field on the ground state of ferroelectric Ba0.7Sr0.3TiO3 thin films, deposited on the cubic (0 0 1) substrate. The dependence of the pyroelectric coefficient on the applied field is calculated for the different values of the induced strain. We found that tuning of the misfit strain in the film under the dielectric bolometer mode by the proper selection of substrate makes it possible to create the structures with very large values of the pyroelectric coefficient.
