17 research outputs found
Laser-Induced Skyrmion Writing and Erasing in an Ultrafast Cryo-Lorentz Transmission Electron Microscopy
We demonstrate that light-induced heat pulses of different duration and
energy can write skyrmions in a broad range of temperatures and magnetic field
in FeGe. Using a combination of camera-rate and pump-probe cryo-Lorentz
Transmission Electron Microscopy, we directly resolve the spatio-temporal
evolution of the magnetization ensuing optical excitation. The skyrmion lattice
was found to maintain its structural properties during the laser-induced
demagnetization, and its recovery to the initial state happened in the
sub-{\mu}s to {\mu}s range, depending on the cooling rate of the system
A transverse current rectification in graphene superlattice
A model for energy spectrum of superlattice on the base of graphene placed on
the striped dielectric substrate is proposed. A direct current component which
appears in that structure perpendicularly to pulling electric field under the
influence of elliptically polarized electromagnetic wave was derived. A
transverse current density dependence on pulling field magnitude and on
magnitude of component of elliptically polarized wave directed along the axis
of a superlattice is analyzed.Comment: 12 pages, 6 figure
АКТИВНАЯ АНТЕННА ДЛЯ ПРИЕМА СИГНАЛОВ СПУТНИКОВЫХ СИСТЕМ GPS/ГЛОНАСС/EGNOS
The article describes the result of development and laboratory testing of the active antenna for receiving signals of satellite systems GPS/GLONASS/EGNOS with powered from the RF cable. The antenna element is designed on a ceramic substrate with high permittivity and reduced dimensions.Приведены результаты разработки и лабораторных испытаний технологичной активной антенны на керамической подложке с уменьшенными размерами и питанием по радиочастотному кабелю, обеспечивающей прием сигналов спутниковых систем GPS, ГЛОНАСС и EGNOS
Electric-Field-Driven Topological Phase Switching and Skyrmion-Lattice Metastability in Magnetoelectric Cu2OSeO3
Direct electric field control of the skyrmion phase in a magnetoelectric insulator
Magnetic skyrmions are topologically protected spin-whirls currently considered as promising for use in ultra-dense memory devices. Towards achieving this goal, exploration of the skyrmion phase response and under external stimuli is urgently required. Here we show experimentally, and explain theoretically, that in the magnetoelectric insulator Cu2OSeO3 the skyrmion phase can expand and shrink significantly depending on the polarity of a moderate applied electric field (few V/μm). The theory we develop incorporates fluctuations around the mean-field that clarifies precisely how the electric field provides direct control over the free energy difference between the skyrmion and the surrounding conical phase. The quantitative agreement between theory and experiment provides a solid foundation for the development of skyrmionic applications based on magnetoelectric coupling
Dynamics of feed water flow rate control system with low- noise regulator
We present the results of modeling a feed water control system. The system contains two regulatory devices the feed valve to control the flow rate, with electrohydraulic control, and the throttle valve to maintain constant pressure differential on the feed valve, with hydromechanical control. The valves have perforated flow parts to reduce hydrodynamic noise and vibration, which necessitates checking the dynamical characteristics of the system. The model was developed on the basis of equations describing the electrohydraulic converter dynamics, a differential pressure meter, a servo drive and flow parts with the use of Matlab Simulink. The modeling of dynamical processes caused by various disturbance inputs and control actions showed the compliance of the system with the requirements imposed on it