26 research outputs found
An Electronic Band Structure Calculation and the Optical Properties of Alkaline-Earth Sulphides
Image of the Scientist in Context of Comparison of the German and Israeli Scientific Mediadiscourse in the Field of Research in Quantum Nanotechnologies (on Materials of Magazines «Max Planck Forschung» and «Technion» from 2007 to 2017)
Статья основана на сравнении немецкого и израильского медиадискурса в области исследования квантовых нанотехнологий. В рассматриваемых журнальных материалах выявлено, что амплитуда развития научных интересов в обеих странах вызвана потребностью каждого из государств. В ходе анализа темы конструируется образ ученого, проявляющего типичные для представителей научного сообщества черты. Индивидуальный образ ученого можно представить как исследователя, работающего в авангарде науки на стыке междисциплинарности и развивающего традиции своей научной школы. Формирование такого образа способствует повышению престижа профессии ученого в сфере квантовых нанотехнологий.The paper is based on a comparison of German and Israeli media discourse in the field of research in quantum nanotechnologies. In these magazines it is revealed that the amplitude of development of scientific interests in both countries depends on the needs of each state. Analysis of the topic the image of a scientist is constructed, who shows features typical for representatives of the scientific community. The individuals’ image of nano-scientists can be generally abstracted as a researcher who works at the forefront of science at the intersection of interdisciplinarity and develops the traditions of his scientific school. The formation of such an image contributes to increasing the prestige of the scientist's profession in the field of quantum nanotechnology
Jet-like tunneling from a trapped vortex
We analyze the tunneling of vortex states from elliptically shaped traps.
Using the hydrodynamic representation of the Gross-Pitaevskii (Nonlinear
Schr\"odinger) equation, we derive analytically and demonstrate numerically a
novel type of quantum fluid flow: a jet-like singularity formed by the
interaction between the vortex and the nonhomogenous field. For strongly
elongated traps, the ellipticity overwhelms the circular rotation, resulting in
the ejection of field in narrow, well-defined directions. These jets can also
be understood as a formation of caustics since they correspond to a convergence
of trajectories starting from the top of the potential barrier and meeting at a
certain point on the exit line. They will appear in any coherent wave system
with angular momentum and non-circular symmetry, such as superfluids,
Bose-Einstein condensates, and light.Comment: 4 pages, 4 figure
Dynamics of fluctuations in an optical analog of the Laval nozzle
Using the analogy between the description of coherent light propagation in a
medium with Kerr nonlinearity by means of nonlinear Schr\"odinger equation and
that of a dissipationless liquid we propose an optical analogue of the Laval
nozzle. The optical Laval nozzle will allow one to form a transonic flow in
which one can observe and study a very unusual dynamics of classical and
quantum fluctuations including analogue of the Hawking radiation of real black
holes. Theoretical analysis of this dynamics is supported by numerical
calculations and estimates for a possible experimental setup are presented.Comment: 7 pages, 4 figure
Pilot Survey of Autistic School Staff Who Work or Have Worked in an Education Role in Schools in the UK: Initial Summary Report
Green's function method for calculation of adsorption of organic molecules on noble metal nanoparticles
Anumerical method for the calculation of electronic structure of a nanosystem composed of a pseudoisocyanine (PIC) molecule assembled on a silver nanoparticle is developed. The electronic structure of the silver nanoparticle containing 125 atoms is calculated within the local density version of the density functional method. A model of an Ag atom embedded in the center of a spherical jellium cluster is used. The host electron Green's function is calculated by means of the spherically symmetric expansion. The principal theoretical tool is the scattering theory using the Green's function method. The molecule-silver nanosystem interaction is studied using the approach similar to that of the Anderson model for transition metal impurities in solids. Localized levels are shown to split off from the top of the band of the Ag nanoparticle. The electronic structure calculations yield information on the character of chemical bonding in the PIC molecule-silver particle nanosystem