arXiv subjects

Svitlana Kondovych

Publications and source records attributed to Svitlana Kondovych.

7 recordsLinked to original sources

arXiv2026

Unconventional criticality in $O(D)$-invariant loop-constrained Landau theory

We study an unconventional phase transition in ferroelectrics where the polarization field is constrained to be divergence-free, allowing only loop-like configurations. This local constraint fundamentally alters the critical behavior, driving the system beyond the Landau-Ginzburg-Wilson paradigm. A renormalization group analysis shows that the polarization acquires an unusually large anomalous dimension, $η\approx 0.239$ in three dimensions, far exceeding the typical values in $O(3)$-invariant systems. We attribute this effect to a naturally induced gauge symmetry originating from the zero divergence constraint. Such gauge-field behavior is reminiscent of fractionalized phases, revealing a fundamental connection between constrained ferroelectrics and emergent gauge phenomena in correlated matter.

cond-mat.mes-hall↗

arXiv2025

Morphology of Polarization States in Strained Ferroelectric Films

Ferroelectric thin films under epitaxial strain exhibit a variety of vortex-like topological polarization textures. To analyze them, we build on the Ginzburg-Landau-Devonshire framework and extend the previously introduced soft-domain approach. This formulation provides a compact variational theoretical description of polarization morphologies in strained PbTiO$_3$ films. It yields phase diagrams as a function of temperature, strain, and thickness, and clarifies the morphological structure of emergent topological states. The method is computationally efficient and offers practical guidance for experimental studies of ferroelectric nanostructures.

cond-mat.mtrl-sci↗

arXiv2025

Chiral breakdown engineered by mesoscale Dzyaloshinskii-Moriya interaction in biaxial magnetic nanotubes

Curvilinear geometries in magnetic nanostructures provide a unique platform for exploring the interplay of symmetry, topology, and curvature in magnetization dynamics. In this work, we analytically study the static and dynamic properties of domain walls in biaxial magnetic nanotubes with intrinsic Dzyaloshinskii-Moriya interaction of different symmetries. We show that geometry-driven local and nonlocal interactions govern domain profiles and dynamics, enabling precise control over the wall propagation and Walker breakdown field. Furthermore, the combination of bulk-type Dzyaloshinskii-Moriya interaction and curvature leads to chirality symmetry breaking and chiral breakdown in domain wall motion. These findings offer a framework for tailoring domain wall textures in cylindrical nanotubes, unlocking new functionalities for advanced applications in curvilinear magnonics and data storage technologies.

cond-mat.mes-hall↗

arXiv2024

Topological ferroelectric chirality

Chirality, an inherent property of most objects of the universe, is a dynamic research topic in material science, physics, chemistry, and biology. The fundamental appeal of this extensive study is supported by the technological quest to manufacture materials with configurable chiralities for emerging applications ranging from optoelectronics and photonics to pharmaceutics and medicine. Recent advances put forth ferroelectrics as a host of chiral topological states in the form of Bloch domain walls, skyrmions, merons, and Hopfions, offering thus a unique ground for making chirality switchable and tunable. Here we review current developments, milestones achieved, and future routes of chiral ferroelectric materials. 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 and enantioselectivity, leading to new applications in nano-optoelectronics, plasmonics, pharmaceutics, and bio-medical industries.

cond-mat.mtrl-sci↗

arXiv2022

Vortex states in a PbTiO$_3$ ferroelectric cylinder

The past decade's discovery of topological excitations in nanoscale ferroelectrics has turned the prevailing view that the polar ground state in these materials is uniform. However, the systematic understanding of the topological polar structures in ferroelectrics is still on track. Here we study stable vortex-like textures of polarization in the nanocylinders of ferroelectric PbTiO$_3$, arising due to the competition of the elastic and electrostatic interactions. Using the phase-field numerical modeling and analytical calculations, we show that the orientation of the vortex core with respect to the cylinder axis is tuned by the geometrical parameters and temperature of the system.

cond-mat.mes-hall↗

arXiv2021

Gate-tunable electron interaction in high-κ dielectric films

The two-dimensional (2D) logarithmic character of Coulomb interaction between charges and the resulting logarithmic confinement is a remarkable inherent property of high dielectric constant (high-$κ$) thin films with far reaching implications. Most and foremost, this is the charge Berezinskii-Kosterlitz-Thouless transition with the notable manifestation, low-temperature superinsulating topological phase. Here we show that the range of the confinement can be tuned by the external gate electrode and unravel a variety of electrostatic interactions in high-$κ$ films. We find that by reducing the distance from the gate to the film, we decrease the spatial range of the 2D long-range logarithmic interaction, changing it to predominantly dipolar or even to exponential one at lateral distances exceeding the dimension of the film-gate separation. Our findings offer a unique laboratory for the in-depth study of topological phase transitions and related phenomena that range from criticality of quantum metal- and superconductor-insulator transitions to the effects of charge-trapping and Coulomb scalability in memory nanodevices.

cond-mat.mes-hall↗

arXiv2016

Nondestructive method of thin film dielectric constant measurements by two-wire capacitor

We suggest the nondestructive method for determination of the dielectric constant of substrate-deposited thin films by capacitance measurement with two parallel wires placed on top of the film. The exact analytical formula for the capacitance of such system is derived. The functional dependence of the capacitance on dielectric constants of the film, substrate, and environment media and on the distance between the wires permits to measure the dielectric constant of thin films for the vast set of parameters where previously proposed approximate methods are less efficient.

cond-mat.mes-hall↗