In ferroelectrics, complex interactions among various degrees of freedom enable the condensation of topologically protected polarization textures. Known as ferroelectric solitons, these particle-like structures represent a new class of materials with promise for beyond-CMOS technologies due to their ultrafine size and sensitivity to external stimuli. Such polarization textures have scarcely been demonstrated in multiferroics. Here, we present evidence for ferroelectric solitons in (BiFeO)/(SrTiO) superlattices. High-resolution piezoresponse force microscopy and Cs-corrected high-angle annular dark-field scanning transmission electron microscopy reveal a zoo of topologies, and polarization displacement mapping of planar specimens reveals center-convergent/divergent topological defects as small as 3 nm. Phase-field simulations verify that some of these structures can be classed as bimerons with a topological charge of ±1, and first-principles-based effective Hamiltonian computations show that the coexistence of such structures can lead to non-integer topological charges, a first observation in a BiFeO-based system. Our results open new opportunities in multiferroic topotronics.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC10345089 | PMC |
http://dx.doi.org/10.1038/s41467-023-39841-3 | DOI Listing |
Heliyon
November 2024
Laboratory of Research on Advanced Materials and Nonlinear Sciences, Department of Physics, Faculty of Science, University of Buea, P.O. Box 63, Buea, Cameroon.
In the present work, we focus on the longitudinal model of microtubules (MTs) proposed by Satarić et al. (1993) [12], and that considers MT cells to have ferroelectric properties (behaviors) due to dipolar oscillations of dimers within MTs, i.e.
View Article and Find Full Text PDFSmall
December 2024
Materials Research Centre, Indian Institute of Science, Bangalore, Karnataka, 560012, India.
Topological polar soliton such as skyrmions, merons, vortices, flux closures represent topologically nontrivial structures with their stability governed by specific boundary conditions. These polar solitons can be utilized in enhancing memory density and reducing energy consumption in nanoelectronic devices. Flux closure domains exhibit high density and thermal stability, with a strain gradient as large as ≈10 m at the core, which is tunable by adjusting the materials thickness, periodicity.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
December 2024
Tandon School of Engineering, Chemical and Biomolecular Engineering, New York University, Brooklyn, NY 11201.
Emergent electronic phenomena, from superconductivity to ferroelectricity, magnetism, and correlated many-body band gaps, have been observed in domains created by stacking and twisting atomic layers of Van der Waals materials. In graphene, emergent properties have been observed in ABC stacking domains obtained by exfoliation followed by expert mechanical twisting and alignment with the desired orientation, a process very challenging and nonscalable. Here, conductive atomic force microscopy shows in untwisted epitaxial graphene grown on SiC the surprising presence of striped domains with dissimilar conductance, a contrast that demonstrates the presence of ABA and ABC domains since it matches exactly the conductivity difference observed in ABA/ABC domains in twisted exfoliated graphene and calculated by density functional theory.
View Article and Find Full Text PDFSci Rep
November 2024
Department of Physics, College of Khurma University College, Taif University, P.O. Box 11099, Taif, 21944, Saudi Arabia.
Nat Mater
July 2024
Laboratoire Albert Fert, CNRS, Thales, Université Paris-Saclay, Palaiseau, France.
Topologically protected spin whirls in ferromagnets are foreseen as the cart-horse of solitonic information technologies. Nevertheless, the future of skyrmionics may rely on antiferromagnets due to their immunity to dipolar fields, straight motion along the driving force and ultrafast dynamics. While complex topological objects were recently discovered in intrinsic antiferromagnets, mastering their nucleation, stabilization and manipulation with energy-efficient means remains an outstanding challenge.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!