Tunable topological chirality in ferroelectric nanomaterials
PRINCIPAL INVESTIGATOR
Dr. Anna Razumnaya
Chirality 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. Very recently we discovered that chiral structure emerges as a basic configuration of polarization field in ferroelectric nanoparticles and nanodots in a form of stable fundamental topological excitations of polarization, Hopfions, and skyrmions, and, importantly, can be controlled and switched by cleverly devised field-temperature protocols. The key idea of the project is to reveal how this discovered emerging topological chirality will be identified, measured, explored, and put in practice.
DAN ODPRTIH VRAT
Open Doors_JSI_Razumnaya_slo_A1.pdfLet's build the materials of tomorrow!
INNOVATIVE TOPOLOGICAL ROUTES
INNOVATIVE TOPOLOGICAL ROUTES
Open days at Jozef Stefan Institute, Slovenia
for schoolchildren and their parents
for everyone interested in modern developments in science
Mar. 2024. Dr Anna Razumnaya, within EU-FerroChiral project, organized a presentation on an open day at Jozef Stefan Institute.
Information about ferroic materials was presented with outstanding properties potentially useful for applications in different fields of science and technology.
Let's build the materials of tomorrow!
Open-door day at the University of Picardy Jules Verne, France
Feb. 2024. An international group consisting of participants from three European Marie Curie mobility projects: RISE-MELON: Igor Lukyanchuk (France) and Marcelo Sepliarsky (Argentina) ITN-MANIC: Yurii Tikhonov and IF-FerroChiral: Anna Razumnaya organized a presentation at an open-door day at the University of Picardy, UPJV. Schoolchildren planning to enter the university enjoyed listening to the explanation of scientists about future computers that will be based on new principles of neuromorphic and multilevel logic, as well as about the possibility of controlling chirality by electrical switching.
The university expressed gratitude to the researchers.
April 9th, 2024
Joint Workshop of HORIZON-EU networks:
MSCA-RISE-MELON & WIDERA-FerroChiral :
Invited talk "Topological polarization states in nanostructured ferroelectrics"
Emergent Topological Chirality in Ferroics
The past decade marked breakthrough discoveries of novel topological polarization structures in nanostructured ferroelectrics. The observed polarization structures have been interpreted in terms of the real-space vector field topology as multiple combinations of vortices, skyrmions, merons, and other topological formations, previously observed in magnetic systems. However, this visible analogy misses ferroelectricity's cornerstone, the dominant role of the long-range electrostatic forces. In this talk, we present a generic topological foundation of ferroelectricity arising from its electrostatic essence and discuss from this viewpoint the recent trends in the field. We review the observed polarization topological structures and show that their rich variety can be exhaustively described by the fundamental formations, vortices, and Hopfions. Remarkably, the emergence of the latter provides the chirality of the confined ferroelectric systems. We focus on insights into the topological origin of the chirality in the nanostructured ferroelectrics, bringing new controllable functionalities. We pay special attention to novel developments enabling tunability and manipulating the chiroptical response in ferroelectric nanoparticles and nanodots.
Workshop "Nanomaterials for neuromorphic computing and energy harvesting"
March 14-18, 2023, San Carlos de Bariloche, Argentina
Joint Workshop of HORIZON-EU networks:
MSCA-RISE-ENGIMA, MSCA-RISE-MELON &
WIDERA-TALENTS-FerroChiral :
Invited talk "Ferroelectrics in the vicinity of quantum critical point: towards tunable topological chirality"
APS March Meeting 2023
March 5-10, 2023, Las Vegas, USA
The APS March Meeting brings together scientists and students from around the world to connect and collaborate across academia, industry, and major labs. Students, early-career physicists, and experienced professionals will benefit from the networking and learning at March Meeting.
Oral talk "Properties of incipient ferroelectrics in the vicinity of quantum critical point "
S. Kondovych, Y. Tikhonov, M. Pavlenko, A. Razumnaya, V. Vinokur, I. Luk'yanchuk. “Topological polar phases in confined ferroelectrics”
FINI 2023
November 24-25, 2022, Novo Mesto, Slovenia
7th International Conference on the Development of Industrial Engineering: Opportunities, Potentials, Challenges
The purpose of the conference is to activate and implement practices of international conferences with an emphasis of collaboration among businesses and higher education institutions. The aim is to ensure uniformity of developing tendencies to the growing need of key employees from technical and industrial fields that would consequently lead to alignment of labour market needs, business development, economic competitiveness and as a result the needs of societal and cultural environments. The conference covers several thematic sections and joins delegates from leading industrial corporations, research institutes as well as higher education institutions from Slovenia and abroad.
Oral talk "Spectral response of incipient ferroelectrics"
Publications (Topology, Chirality, Switching)
Here we propose using the ferroelectric logic unit comprising multiple ferroelectric nanodots disposed between two electrodes and coated by the dielectric material, providing topologically configurable non-binary logic into a gate stack of the field-effect transistor as an analog-like device with resistive states. By controlling the charge of the gate, we demonstrate the various routes of the topological switchings between different polarization configurations in ferroelectric nanodots.
Here we study stable vortex-like textures of polarization in the nanocylinders of ferroelectric PbTiO3, arising due to the competition of the elastic and electrostatic interactions. We demonstrate that the orientation of the vortex core with respect to the cylinder axis is tuned by the geometrical parameters and temperature of the system.
Here we report a mechanism wiping out the polarization discontinuity (appearing when antiparallel domains meet) in the uniaxial ferroelectrics possessing low domain wall conductivity. This mechanism consists in forming the specific configuration of the polarization vector field with the mutual domain bifurcation. It creates the characteristic saddle-point domain wall morphology removing the need for the screening charge accumulation and associated conductivity enhancement.
Here we put forth an ingenious design for the ferroelectric domain-based field-effect transistor with stable reversible static negative capacitance. Using a dielectric coating of the ferroelectric capacitor enables the tunability of the negative capacitance improving tremendously the performance of the field-effect transistors.
Here we devise protocols for realizing control and efficient manipulations of the skyrmions with different chirality in ferroelectric nanodots. Our findings open the route for controlled chirality with potential applications in ferroelectric-based information technologies.
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.
Here, we show that the ferroelectric nanodot capacitor hosts a stable two-domain state realizing the static reversible negative capacitance device thus opening routes for the extensive use of the negative capacitance in domain wall-based nanoelectronics.
Networking
Contacts
e-mail: anna.razumnaya@ijs.si
