arXiv subjects

Mykhailo I. Bratchenko

Publications and source records attributed to Mykhailo I. Bratchenko.

3 recordsLinked to original sources

arXiv2026

Helicity-Controlled Hall Transport in Hybrid Topological Magnetic Textures

Topological magnetic textures can serve as information carriers driven by spin currents. However, their motion is generally accompanied by a Hall effect that deflects them from the current direction, limiting transport efficiency and controllability. We develop a unified spin-space transformation framework enabling a systematic study of hybrid spin textures with different helicities, such as skyrmions, antiskyrmions, bimerons, and antibimerons. Combining analytical theory with micromagnetic simulations, we establish the relation between helicity and current-driven transport. An analytical solution of the generalized Thiele equation identifies helicity as a geometric control parameter and yields a simple expression for the Hall angle, enabling its continuous tuning, complete suppression, and deterministic steering along arbitrary in-plane directions. Micromagnetic simulations confirm that the generated spin textures remain stable under Landau--Lifshitz--Gilbert dynamics and validate the analytical predictions. These results establish helicity as a versatile control parameter for programmable transport of topological magnetic textures.

cond-mat.mes-hall↗

arXiv2026

Stochastic Dynamics of Domain Wall on a Racetrack: Impact of Line-Edge Roughness

We investigate the impact of line-edge roughness on current-driven domain wall dynamics in ferromagnetic racetracks. Modeling the edge disorder as a spatially correlated Ornstein-Uhlenbeck process, we demonstrate that even minimal experimentally relevant roughness induces pronounced stochastic pinning of domain walls. Notably, this stochasticity of the current-driven motion arises purely from spatial disorder, even in the absence of thermal fluctuations. The probability of a domain wall to reach a given position exhibits a robust sigmoidal dependence on the applied current, reflecting an effective distribution of depinning thresholds. At the same time, the underlying dynamics is highly nontrivial: the mean velocity exhibits a nonlinear dependence on both time and current, while the mean-square displacement exhibits a ballistic regime at short times followed by saturation due to trapping at pinning sites. These results demonstrate that line-edge roughness provides a controllable source of stochasticity and enables p-bit-like functionality in racetrack systems, offering a pathway toward hardware implementations of probabilistic and neuromorphic computing.

cond-mat.dis-nn↗

arXiv2026

Stochastic Dynamics of Skyrmions on a Racetrack: Impact of Equilibrium and Nonequilibrium Noise

Current-driven motion of domain walls and skyrmions is central to the operation of non-volatile magnetic memory devices. Racetrack memory requires current densities high enough to generate velocities above 50 m/s, but such conditions also enhance spin-current noise. We develop a theoretical framework based on the stochastic Thiele equation to analyze the effects of equilibrium (thermal) and nonequilibrium (spin-current) fluctuations on skyrmion dynamics. From this approach, we derive diffusion coefficients and mean-squared displacements that quantify stochastic motion under both noise sources. Micromagnetic simulations and analytical results demonstrate that spin-current noise dominates skyrmion dynamics in typical racetrack structures up to room temperature. We further address the first-passage-time problem, obtaining the mean first-passage time and its standard deviation along and across the racetrack. These results quantify how random displacements affect skyrmion propagation and detection, providing insights into error sources in high-speed racetrack memory devices.

cond-mat.dis-nn↗