A5018364791- Ferroelectric and Piezoelectric Materials
- Multiferroics and related materials
- Acoustic Wave Resonator Technologies
- Magnetic properties of thin films
- Electronic and Structural Properties of Oxides
- Theoretical and Computational Physics
- Magnetic and transport properties of perovskites and related materials
- Characterization and Applications of Magnetic Nanoparticles
- Physics of Superconductivity and Magnetism
- Microwave Dielectric Ceramics Synthesis
- Machine Learning in Materials Science
- Photonic Crystals and Applications
- Liquid Crystal Research Advancements
- Perovskite Materials and Applications
- Magneto-Optical Properties and Applications
- Dielectric materials and actuators
- Advanced Memory and Neural Computing
- Photorefractive and Nonlinear Optics
- Metamaterials and Metasurfaces Applications
- Topological Materials and Phenomena
- Neural Networks and Reservoir Computing
- Material Dynamics and Properties
- Boron and Carbon Nanomaterials Research
- Ferroelectric and Negative Capacitance Devices
- Advanced Condensed Matter Physics
University of Arkansas at Fayetteville
2016-2025
Universidad de Cantabria
2023
Harbin Institute of Technology
2023
University of Liège
2017-2020
UNSW Sydney
2019
Materials Science & Engineering
2019
Southern University of Science and Technology
2019
University of Nebraska–Lincoln
2019
École Centrale Paris
2012-2014
Peter the Great St. Petersburg Polytechnic University
2014
abinit is probably the first electronic-structure package to have been released under an open-source license about 20 years ago. It implements density functional theory, density-functional perturbation theory (DFPT), many-body (GW approximation and Bethe–Salpeter equation), more specific or advanced formalisms, such as dynamical mean-field (DMFT) “temperature-dependent effective potential” approach for anharmonic effects. Relying on planewaves representation of wavefunctions, density, other...
Abstract Non-coplanar swirling field textures, or skyrmions, are now widely recognized as objects of both fundamental interest and technological relevance. So far, skyrmions were amply investigated in magnets, where due to the presence chiral interactions, these topological found be intrinsically stabilized. Ferroelectrics on other hand, lacking such somewhat left aside this quest. Here we demonstrate, via use a first-principles-based framework, that skyrmionic configuration polarization can...
Magnetic skyrmions are nano-scale spin structures that promising for ultra-dense memory and logic devices. Recent progresses in two-dimensional magnets encourage the idea to realize skyrmionic states freestanding monolayers. However, monolayers such as CrI3 lack Dzyaloshinskii-Moriya interactions (DMI) thus do not naturally exhibit but rather a ferromagnetic state. Here we propose fabrication of Cr(I,X)3 Janus monolayers, which Cr atoms covalently bonded underlying I ions top-layer Br or Cl...
Topology provides a framework for an understanding of emergent phenomena in various fields such as the appearance new results field ferroelectrics. A historical introduction and primer on concepts topology are followed by discussion experimental theoretical methods that elucidate exotic textures appear polar oxide nanostructures superlattices. The complex interplay several fundamental processes occurring different energy scales leads to ground states compete with one another have large...
Abstract Observation of a new type nanoscale ferroelectric domains, termed as “bubble domains”—laterally confined spheroids sub‐10 nm size with local dipoles self‐aligned in direction opposite to the macroscopic polarization surrounding matrix—is reported. The bubble domains appear ultrathin epitaxial PbZr 0.2 Ti 0.8 O 3 /SrTiO /PbZr sandwich structures due interplay between charge and lattice degrees freedom. existence is revealed by high‐resolution piezoresponse force microscopy (PFM),...
Quantum spin liquids (QSLs) form an extremely unusual magnetic state in which the spins are highly correlated and fluctuate coherently down to lowest temperatures, but without symmetry breaking formation of any static long-range-ordered magnetism. Such intriguing phenomena not only great fundamental relevance themselves, also hold promise for quantum computing information. Among different types QSLs, exactly solvable Kitaev model is attracting much attention, with most proposed candidate...
Utilization of van der Waals magnetic materials as the host topologically protected skyrmionic and other complex spin textures has been drawing increasing attention. Here, using first-principles-based calculations, we predict a new stable ${\mathrm{CrGe}(\mathrm{Se},\mathrm{Te})}_{3}$ Janus monolayer with strong Dzyaloshinskii-Moriya interaction (DMI), due to breaking inversion symmetry. Consequently, nanometric skyrmions (that carry topological charge $\ifmmode\pm\else\textpm\fi{}1$)...
Abstract In light of directives around the world to eliminate toxic materials in various technologies, finding lead-free with high piezoelectric responses constitutes an important current scientific goal. As such, recent discovery a large electromechanical conversion near room temperature (1− x )Ba(Zr 0.2 Ti 0.8 )O 3 − (Ba 0.7 Ca 0.3 )TiO compounds has directed attention understanding its origin. Here, we report development large-scale atomistic scheme providing microscopic insight into this...
Polar skyrmions are topologically stable, swirling polarization textures with particle-like characteristics, which hold promise for next-generation, nanoscale logic and memory. While understanding of how to create ordered polar skyrmion lattice structures such structure respond applied electric fields, temperature, film thickness remains elusive. Here, using phase-field simulations, the evolution topology emergence a phase transition hexagonal close-packed is explored through construction...
Electric bubbles are sub-10nm spherical vortices of electric dipoles that can spontaneously form in ultra-thin ferroelectrics. While the static properties well established, little to nothing is known about dynamics these particle-like structures. Here, we reveal pathways realizing both spontaneous and controlled Pb(Zr
Twisted light carries a nonzero orbital angular momentum, that can be transferred from to electrons and particles ranging nanometers micrometers. Up now, the interplay between twisted with dipolar systems has scarcely been explored, though latter bear abundant forms of topologies such as skyrmions embrace strong light-matter coupling. Here, using first-principles-based simulations, we show excite drive dynamical polar transfer its winding number ferroelectric ultrathin films. The skyrmion is...
Abstract Whilst often discussed as non-trivial phases of low-dimensional ferroelectrics, modulated polar such the dipolar maze and nano-bubble state have been appraised essentially distinct. Here we emphasize their topological nature show that these self-patterned states, but also additional mesophases disconnected labyrinthine phase mixed bimeron-skyrmion phase, can be fathomed in plurality through unifying canvas separation kinetics. Under compressive strain, varying control parameter,...
Distinct and novel features of nanometric electric topological defects, including dipole waves disclinations, are presently revealed in the PbTiO_{3} layers PbTiO_{3}/SrTiO_{3} multilayer films by means quantitative high-resolution scanning transmission electron microscopy. These original configurations confirmed explained atomistic simulations have potential to act as functional elements future electronics.
Abstract Domain walls in ferroelectric materials have tantalizing potential disruptive memory and reconfigurable nanoelectronics technologies. Here, a domain wall switch with three distinct addressable resistance states is demonstrated. The device operation hinges on fully controllable reversible conformational changes of the wall. As validated by atomistic simulations consistent experiments, using electric field, shape—and hence charge state—of ultimately its conduction are altered....
In ferroelectrics, complex interactions among various degrees of freedom enable the condensation topologically protected polarization textures. Known as ferroelectric solitons, these particle-like structures represent a new class materials with promise for beyond-CMOS technologies due to their ultrafine size and sensitivity external stimuli. Such textures have scarcely been demonstrated in multiferroics. Here, we present evidence solitons (BiFeO3)/(SrTiO3) superlattices. High-resolution...
Nanoscale ferroelectric topologies such as vortices, antivortices, bubble patterns, etc., are stabilized in thin films by a delicate balance of both mechanical and electrical boundary conditions. A systematic understanding the phase stability domains, particularly when above factors act simultaneously, remains elusive. Here we present first-principle-based simulations combination with scanning probe microscopy ultrathin epitaxial (001)...
Vortex crystals are commonly observed in ultrathin ferroelectrics. However, a clear physical picture of origin this topological state is currently lacking. Here, we show that vortex crystallization $\mathrm{Pb}({\mathrm{Zr}}_{0.4},{\mathrm{Ti}}_{0.6}){\mathrm{O}}_{3}$ films stems from the softening phonon mode and can be described as ${Z}_{2}\ifmmode\times\else\texttimes\fi{}\mathrm{SU}(1)$ symmetry-breaking transition. This result sheds light on topology polar patterns bridges vortices with...
Geometric representation lays the basis for understanding and flexible tuning of topological transitions in many physical systems. An example is given by Poincar\'{e} sphere (PS) that provides an intuitive continuous parameterization spin or orbital angular momentum (OAM) light states. Here, we apply this geometric construction to understand continuously encode dynamical topologies ferroelectric solitons driven OAM-tunable light. We show that: (1) PS engineering enables controlled creation...
Abstract Electro-optic effects allow control of the ow light using electric fields, and are utmost importance for today’s information communication technologies, such as TV displays fiber optics. The search large electro-optic constants in films is essential to miniaturization increased efficiency devices. In this work, we demonstrate that strain-engineering PbTiO 3 allows selectively choose which constant improve. Unclamped larger than 100 pm V − 1 predicted, either by driving softening an...