Dynamics of streamer discharge development in semiconductors

Space-time dynamics of streamer discharges in semiconductors in view of processes of shock (tunnel and photo-) ionization, radiating spontaneous and stimulated recombination as well as electron-photon interaction in a strong electric field has been modeled. The possibility of formation in these conditions of space-nonuniform dissipative structures, self-oscillatory regular and other modes were shown; their laws and interrelation with dynamics of streamer laser discharge were established. Nonmonotonic dependence of system characteristics on key parameters - excitation rate, life time of nonequilibrium carriers and photons, quantum efficiency of active environment as well as strengthening of structure interaction in conditions of stimulated recombination causing variety of own system dynamics were revealed. Radiating processes provide high speed of structure distribution compared with phase speed of light, and they are the basic generation mechanism of nonequilibrium carriers generation in self-oscillatory mode respective to optimum conditions of streamer occurrence and developmen

Numerical simulation of coupled electron devices and circuits by the MEP hydrodynamical model for semiconductors with Crystal heating

Solutions of a new 2d semiconductor numerical model describing the electron transport in semiconductors coupled with the heating of the Crystal lattice are presented. The model equations have been obtained with the use of the maximum entropy principle. Numerical simulations of a nanoscale MOSFET and inverter circuit are presented and the influence of self-heating on the electrical characteristics is analyzed

Residues and Topological Yang-Mills Theory in Two Dimensions

A residue formula which evaluates any correlation function of topological $SU_n$ Yang-Mills theory with arbitrary magnetic flux insertion in two dimensions are obtained. Deformations of the system by two form operators are investigated in some detail. The method of the diagonalization of a matrix valued field turns out to be useful to compute various physical quantities. As an application we find the operator that contracts a handle of a Riemann surface and a genus recursion relation.Comment: 23 pages, some references added, to appear in Rev.Math.Phy

Optimization of limiting modes of streamer semiconductor laser

The influence of intensive electric and optical fields produced by streamer discharge in wide-gap semiconductor on their spectroscopic properties has been studied. The given effect is developed at appearance of reversed reconstruction of active environment luminescent characteristics. The methods of sufficient increase in durability and efficiency of streamer laser at limiting modes based on application of semiconductor protecting layers of a definite crystallographic orientation and crystal microrelief with element size of light wave length order. Streamer luminescence in new perspective CaGa2S4:Eu, Ca4Ga2S7:Eu compounds is found and studied

Observation of time quasicrystal and its transition to superfluid time crystal

We report experimental realization of a quantum time quasicrystal, and its transformation to a quantum time crystal. We study Bose-Einstein condensation of magnons, associated with coherent spin precession, created in a flexible trap in superfluid $^3$He-B. Under a periodic drive with an oscillating magnetic field, the coherent spin precession is stabilized at a frequency smaller than that of the drive, demonstrating spontaneous breaking of discrete time translation symmetry. The induced precession frequency is incommensurate with the drive, and hence the obtained state is a time quasicrystal. When the drive is turned off, the self-sustained coherent precession lives a macroscopically-long time, now representing a time crystal with broken symmetry with respect to continuous time translations. Additionally, the magnon condensate manifests spin superfluidity, justifying calling the obtained state a time supersolid or a time super-crystal

A quantum group version of quantum gauge theories in two dimensions

For the special case of the quantum group $SL_q (2,{\bf C})\ (q= \exp \pi i/r,\ r\ge 3)$ we present an alternative approach to quantum gauge theories in two dimensions. We exhibit the similarities to Witten's combinatorial approach which is based on ideas of Migdal. The main ingredient is the Turaev-Viro combinatorial construction of topological invariants of closed, compact 3-manifolds and its extension to arbitrary compact 3-manifolds as given by the authors in collaboration with W. Mueller.Comment: 6 pages (plain TeX

Current control in the competence approach

This paper proposes a method of monitoring the knowledge-based test technologies and allows monitoring of formation of partial competencies. The proposed method is illustrated by the example of the course of computer scienceВ работе предлагается методика текущего контроля знаний, основанная на тестовых технологиях и позволяющая осуществлять частичный мониторинг сформированности компетенций. Предлагаемая методика иллюстрируется примером из курса информатик