Method and Experimental Setup for the Study of the Local Current Distribution in Conducting Micro-and Nanostructures

The method for the study of the spatial distribution of current in micro-and nanostructures on the measured magnetic field is presented. The methods of studies the magnetic field distribution of conducting nanostructures by passing a transport current are considered. The technique of current recovery from experimental data is offered. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3522

Disclination vortices in elastic media

The vortex-like solutions are studied in the framework of the gauge model of disclinations in elastic continuum. A complete set of model equations with disclination driven dislocations taken into account is considered. Within the linear approximation an exact solution for a low-angle wedge disclination is found to be independent from the coupling constants of the theory. As a result, no additional dimensional characteristics (like the core radius of the defect) are involved. The situation changes drastically for 2\pi vortices where two characteristic lengths, l_\phi and l_W, become of importance. The asymptotical behaviour of the solutions for both singular and nonsingular 2\pi vortices is studied. Forces between pairs of vortices are calculated.Comment: 13 pages, published versio

Trivalent zirconium and hafnium ions in yttria-based transparent ceramics

Electron paramagnetic resonance spectra of transparent yttria-based ceramics with zirconium and hafnium additives contain signals with close parameters due to paramagnetic Zr3+ and Hf3+ ions, which have similar ground-state electron configurations of [Kr]4d 1 and [Xe]5d 1, respectively. © 2013 Pleiades Publishing, Ltd

Quantum Interaction ϕ44\phi^4_4: the Construction of Quantum Field defined as a Bilinear Form

We construct the solution $\phi(t,{\bf x})$ of the quantum wave equation $\Box\phi + m^2\phi + \lambda:\!\!\phi^3\!\!: = 0$ as a bilinear form which can be expanded over Wick polynomials of the free $in$-field, and where $:\!\phi^3(t,{\bf x})\!:$ is defined as the normal ordered product with respect to the free $in$-field. The constructed solution is correctly defined as a bilinear form on $D_{\theta}\times D_{\theta}$, where $D_{\theta}$ is a dense linear subspace in the Fock space of the free $in$-field. On $D_{\theta}\times D_{\theta}$ the diagonal Wick symbol of this bilinear form satisfies the nonlinear classical wave equation.Comment: 32 pages, LaTe

Charge inhomogeneities due to smooth ripples in graphene sheets

We study the effect of the curved ripples observed in the free standing graphene samples on the electronic structure of the system. We model the ripples as smooth curved bumps and compute the Green's function of the Dirac fermions in the curved surface. Curved regions modify the Fermi velocity that becomes a function of the point on the graphene surface and induce energy dependent oscillations in the local density of states around the position of the bump. The corrections are estimated to be of a few percent of the flat density at the typical energies explored in local probes such as scanning tunnel microscopy that should be able to observe the predicted correlation of the morphology with the electronics. We discuss the connection of the present work with the recent observation of charge anisotropy in graphene and propose that it can be used as an experimental test of the curvature effects.Comment: 9 pages, 5 figures. v2: Abstract and discussion about experimental consequences expande

High-temperature etching of SiC in SF6_{6}/O2_{2} inductively coupled plasma

In this work, we demonstrate an effective way of deep (30 µm depth), highly oriented (90° sidewall angle) structures formation with sub-nanometer surface roughness (R$_{ms}$ = 0.7 nm) in silicon carbide (SiC). These structures were obtained by dry etching in SF$_{6}$/O$_{2}$ inductively coupled plasma (ICP) at increased substrate holder temperatures. It was shown that change in the temperature of the substrate holder in the range from 100 to 300 °C leads to a sharp decrease in the root mean square roughness from 153 to 0.7 nm. Along with this, it has been established that the etching rate of SiC also depends on the temperature of the substrate holder and reaches its maximum (1.28 µm/min) at temperatures close to 150 °C. Further temperature increase to 300 °C does not lead to the etching rate rising. The comparison of the results of the thermally stimulated process and the etching with a water-cooled substrate holder (15 °C) is carried out. Plasma optical emission spectroscopy was carried out at different temperatures of the substrate holder

Исследование игровой задачи торможения диска в случае постоянных управлений

The process of braking a disk in the form of a differential game is studied. The dynamic system is based on the Coulomb friction model. The existence of a game value in the case of constant controls of the players is analyzed for different values of initial velocities and parameters of the disk. The aim is to minimize the braking distance. For each case, the guarantees of the first and second players are examined, and a statement about the existence or nonexistence of a game value is formulated. For example, it is shown that in the case of slip-free braking, there exists a game value, and it is attained when the first player applies the greatest possible control allowing him not to slip and the second player minimizes the friction. In the conclusion of the paper, we prove a final theorem stating that the slip-free mode is the best braking mode for the first player under constant controls. © 2019 Krasovskii Institute of Mathematics and Mechanics. All rights reserved

Numerical Stackelberg Solutions in a Class of Positional Differential Games

We consider a problem of numerical construction of a Stackelberg solution in a differential game with closed-loop information structure and terminal player payoffs. It is divided into two subproblems: the problem of computing of so-called “admissible” motions and the optimization problem on the set of admissible motions. We focus on the latter problem and consider two approaches: enumeration of the follower player payoffs and enumeration of the leader player payoffs. Algorithms implementing both approaches are presented and tested on a model system. © 201

Current and piezoresponse measurements of repolarized regions of thin PbZr54Ti46O3 films

This work was supported by the RFBR grant N 18-32-00092_mol-a