521 research outputs found
Wave Functions and Energies of Magnetopolarons in Semiconductor Quantum Wells
The classification of magnetopolarons in semiconductor quantum wells (QW) is
represented. Magnetopolarons appear due to the Johnson - Larsen effect. The
wave functions of usual and combined magnetopolarons are obtained by the
diodanalization of the Schrodinger equation.Comment: 7 pages, 2 figure
Effect of the Spatial Dispersion on the Shape of a Light Pulse in a Quantum Well
Reflectance, transmittance and absorbance of a symmetric light pulse, the
carrying frequency of which is close to the frequency of interband transitions
in a quantum well, are calculated. Energy levels of the quantum well are
assumed discrete, and two closely located excited levels are taken into
account. A wide quantum well (the width of which is comparable to the length of
the light wave, corresponding to the pulse carrying frequency) is considered,
and the dependance of the interband matrix element of the momentum operator on
the light wave vector is taken into account. Refractive indices of barriers and
quantum well are assumed equal each other. The problem is solved for an
arbitrary ratio of radiative and nonradiative lifetimes of electronic
excitations. It is shown that the spatial dispersion essentially affects the
shapes of reflected and transmitted pulses. The largest changes occur when the
radiative broadening is close to the difference of frequencies of interband
transitions taken into account.Comment: 7 pages, 5 figure
Extracts from Problems of Air Law, a collection of works of the Section of air law of the Aviakhim Society of the USSR and Aviakhim RSFSR
The difficulties of developing a body of international law to govern air travel is discussed. A summary of literature and agreements is presented as well as a brief history. Air space over the poles and the legality of methods of claiming territory in the polar regions is discussed
Transmission of a Symmetric Light Pulse through a Wide QW
The reflection, transmission and absorption of a symmetric electromagnetic
pulse, which carrying frequency is close to the frequency of an interband
transition in a QW (QW), are obtained. The energy levels of a QW are assumed
discrete, one exited level is taken into account. The case of a wide QW is
considered when a length of the pulse wave, appropriate to the carrying
frequency, is comparable to the QW's width. In figures the time dependencies of
the dimensionless reflection, absorption are transmission are represented. It
is shown, that the spatial dispersion and a distinction in refraction indexes
influence stronger reflection.Comment: 8 pages,8 figures with caption
A CDCL-style calculus for solving non-linear constraints
In this paper we propose a novel approach for checking satisfiability of
non-linear constraints over the reals, called ksmt. The procedure is based on
conflict resolution in CDCL style calculus, using a composition of symbolical
and numerical methods. To deal with the non-linear components in case of
conflicts we use numerically constructed restricted linearisations. This
approach covers a large number of computable non-linear real functions such as
polynomials, rational or trigonometrical functions and beyond. A prototypical
implementation has been evaluated on several non-linear SMT-LIB examples and
the results have been compared with state-of-the-art SMT solvers.Comment: 17 pages, 3 figures; accepted at FroCoS 2019; software available at
<http://informatik.uni-trier.de/~brausse/ksmt/
Analogue of the Kubo Formula for Conductivity of Spatially Inhomogeneous Systems and Electric Fields
The average of densities of currents and charges, induced by a weak
electromagnetic field in spatially inhomogeneous are calculated at final
temperatures. The Kubo formula for a conductivity tensor is generalized for
spatially inhomogeneous systems and fields. The contributions containing
electric fields and derivative from fields on coordinates are allocated. The
Semiconductor quantum wells, wires and dots may be considered as spatially
inhomogeneous systems.Comment: 10 page
Elastic Light Scattering by Semiconductor Quantum Dots
Elastic light scattering by low-dimensional semiconductor objects is
investigated theoretically. The differential cross section of resonant light
scattering on excitons in quantum dots is calculated. The polarization and
angular distribution of scattered light do not depend on the quantum-dot form,
sizes and potential configuration if light wave lengths exceed considerably the
quantum-dot size. In this case the magnitude of the total light scattering
cross section does not depend on quantum-dot sizes. The resonant total light
scattering cross section is about a square of light wave length if the exciton
radiative broadening exceeds the nonradiative broadening. Radiative broadenings
are calculated
Ways of Revealing Resistance Against Polygraph Testing
"Itis logical to assume that practically all examined persons involved in events under investigation in one form or another (skilfully or unskilfully) try to resist a polygraph. Considering the easy access to information on modern technologies of carrying out psychophysiological tests in screening (PPT) and ways of fighting against them, the problem of effective attempts at resist ance becomes rather relevant. "(...
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