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A. V. Dik

Publications and source records attributed to A. V. Dik.

2 recordsLinked to original sources

On channeling of charged particles in a single dielectric capillary

We analytically analyse the motion of a nonrelativistic charged particle in a cylindrical single capillary. The effective potential for interaction of a charged particle with the inner surface of a capillary is derived as a sum of the averaged atomic potential of the capillary wall surface and the induced potential defined by collective surface excitations. We have shown that under certain conditions this potential becomes attractive and may hold a particle in a bound state due to the surface excitations that defines a so-called surface channeling regime of motion. For the first time we have evaluated the induced potential revealing two limits to form either a well or a barrier that are delineated by the ratio of the insulator plasmon frequency to the frequency defined by the particle motion in a capillary.

physics.acc-ph

Evolution of vortex pinning in the FeSe$_{1-x}$S$_x$ system

We present a comprehensive study of vortex matter and pinning evolution in the FeSe$_{1-x}$S$_x$ system with various doping degree. The influence of sulphur substitution on vortex pinning and peak effect occurrence is studied. We show that there is a complex interplay among various pinning contributions in the FeSe$_{1-x}$S$_x$ system. Additionally, we study a possible vortex liquid-vortex glass/lattice transition and find an evidence that the vortex liquid-vortex glass phase transition in FeSe has a quasi two-dimensional nature. We investigate the upper critical field behaviour in FeSe$_{1-x}$S$_x$ system, and found that the upper critical field is higher than that predicted by the Werthamer-Helfand-Hohenberg (WHH) model, whereas its temperature dependence could be fitted within a two-band framework. Finally, a detailed H-T phase diagram is presented.

cond-mat.supr-con