New type of stable particle like states in chiral magnets (Chiral bobbers)

We present a new type of a thermodynamically stable magnetic state at interfaces and surfaces of chiral magnets. The state is a soliton solution of micromagnetic equations localized in all three dimensions near a boundary and contains a singularity, but nevertheless has a finite energy. Both features combine to a quasi-particle state for which we expect unusual transport and dynamical properties. It exhibits high thermal stability and thereby can be considered as promising object for fundamental research and practical applications in spintronic devices. We provide arguments that such a state can be found in different B20-type alloys e.g. Mn$_{1-x}$Fe$_x$Ge, Mn$_{1-x}$Fe$_x$Si, Fe$_{1-x}$Co$_x$Si.Comment: accepted in PR

Simulation of the influence of surface chemical composition on internal gas flow at large Knudsen numbers

On the basis of the developed model, an attempt to describe a rarefied gas flow in the cylindrical channel, whose surface chemical composition conforms with the real experimental conditions, has been made. During the modeling two cases are considered: the atomically clean silver channel surface and the surface fully covered with the adsorbate, which is simulated by oxygen according to the data of the Auger-spectroscopic analysis. The gas-surface interaction process is based on the molecular dynamic principle. Thermal vibrations of the surface atoms are also considered. The obtained results of calculation are compared with experimental data. © Copyright 2013 Published by Elsevier Ltd. All rights reserved

Dynamical Toroidal Hopfions in a Ferromagnet with Easy-Axis Anisotropy

Three-dimensional toroidal precession solitons with a nonzero Hopf index, which uniformly move along the anisotropy axis in a uniaxial ferromagnet, have been found. The structure and existence region of the solitons have been numerically determined by solving the Landau-Lifshitz equation.Comment: 6 pages, 4 figure

Magnetic surveys locate Late Bronze Age corrals

A new type of livestock enclosure from the Late Bronze Age has been discovered. Stone walls outline a pair of circular or oval areas that may be up to 50 m in diameter. The stone walls are invisible at the surface; they were discovered in north-western Crimea and only with the aid of remote sensing and geophysical survey

Multi-filament structures in relativistic self-focusing

A simple model is derived to prove the multi-filament structure of relativistic self-focusing with ultra-intense lasers. Exact analytical solutions describing the transverse structure of waveguide channels with electron cavitation, for which both the relativistic and ponderomotive nonlinearities are taken into account, are presented.Comment: 21 pages, 12 figures, submitted to Physical Review