Analytic pulse design for selective population transfer in many-level quantum systems: maximizing amplitude of population oscillations

State selective preparation and manipulation of discrete-level quantum systems such as atoms, molecules or quantum dots is a the ultimate tool for many diverse fields such as laser control of chemical reactions, atom optics, high-precision metrology and quantum computing. Rabi oscillations are one of the simplest, yet potentially quite useful mechanisms for achieving such manipulation. Rabi theory establishes that in the two-level systems resonant drive leads to the periodic and complete population oscillations between the two system levels. In this paper an analytic optimization algorithm for producing Rabi-like oscillations in the general discrete many-level quantum systems is presented.Comment: Published in Phys.Rev.A. This is the final published versio

State-Selective Control For Vibrational Excitation and Dissociation of Diatomic Molecules With Shaped Ultrashort Laser Pulses

Ultrafast state-selective dynamics of diatomic molecules in the electronic ground state under the control of infrared picosecond and femtosecond shaped laser pulses is investigated for the discrete vibrational bound states and for the dissociative continuum states. Quantum dynamics in a classical laser field is simulated for a one-dimensional nonrotating dissociative Morse oscillator, representing the local OH bond in the H2O and HOD molecules. Computer simulations are based on two approaches - exact treatment by the time-dependent Schrödinger equation and approximate treatment by integro-differential equations for the probability amplitudes of the bound states only. Combination of these two approaches is useful to reveal mechanisms underlying selective excitation of the continuum states and above-threshold dissociation in a single electronic state and for designing optimal laser fields to control selective preparation of the high-lying bound states and the continuum states. Optimal laser fields can be designed to yield almost 100% seletive preparation of any prescribed bound state, including those close to the dissociation threshold. State-selective preparation of the highest bound state may be accompanied by the appearance of a quasi-bound molecular state in the continuum with the kinetic energy of the fragments being close to zero. The respective above-threshold dissociation spectrum containes an additional, zero-order peak. The laser-induced dissociation from selectively prepared high-lying bound states is shown to be very efficient, with the dissociation probability approaching the maximal value. Flexible tools of state-selective laser control are developed which enable one to achieve selective control of the dissociation spectra resulting in time-selective and space-selective control of the dissociation fragments

Initial-state dependence of coupled electronic and nuclear fluxes in molecules

We demonstrate that coupled electronic and nuclear fluxes in molecules can strongly depend on the initial state preparation. Starting the dynamics of an aligned D2 + molecule at two different initial conditions, the inner and the outer turning points, we observe qualitatively different oscillation patterns of the nuclear fluxes developing after 30 fs. This corresponds to different orders of magnitude bridged by the time evolution of the nuclear dispersion. Moreover, there are attosecond time intervals within which the electronic fluxes do not adapt to the nuclei motion depending on the initial state. These results are inferred from two different approaches for the numerical flux simulation, which are both in good agreement

Ментальные карты

Current paper is devoted to the mindmapping — one of the modern graphic tools of data recording and visual representation. We demonstrate its advantages in comparison with traditional (linear) way of data recording.Предлагаемая статья посвящена рассмотрению одного из современных графических инструментов визуального представления и записи информации — ментальным картам. Демонстрируются их преимущества перед традиционным (линейным) способом записи

PECULIARITIES OF MANUFACTURING AND APPLICATION OF MIXED EXPLOSIVES OF ANFO TYPE AT MINING ENTERPRISES OF MONGOLIA

The article describes problems of blasting operations carried out at an industrial scale using ammonia-nitrate explosives. Based on experimental studies conducted by the authors, it was determined that for use in mining enterprises in Mongolia, primarily in coal mines, the most rational and effective explosives are mixed ones based on ammonium nitrate in the solid state with various liquid as well as solid dispersed fuels additives - ANFO mixtures. The temperature boundaries for the phase transitions of ammonium nitrate in open areas for the period of three months for different humidity values have been determined. The indicators of oil absorption are identified depending on the cycle of phase transitions for ammonium nitrate

Vibrationally State Selective Photoassociation by Infrared Picosecond Laser Pulses: Model Simulations for O + H → OH(ν)

The quantum dynamics of a photoassociation reaction in the electronic ground state controlled by an infrared picosecond laser pulse is investigated. The association reaction O + H → OH(v) is simulated by representative wavepackets. The OH molecule to be formed is modeled as a non-rotating Morse oscillator. It is shown that the initial free continuum state of O + H can be transferred selectively into a specified vibrational bound state by interaction with an infrared laser pulse. Optimal design of the laser control field leads to high association probability with very high vibrational state-selectivity

Кластеры и денотатные графы

Current paper is devoted to clusters — graphic way of data representation showing notional fields of concepts. Also the paper discuss denotational graphs — way of extraction of the integral descriptors of key notions from a text.Предлагаемая статья посвящена рассмотрению кластеров — графической организации материала, демонстрирующей смысловые поля того или иного понятия, и денотатных графов — способа вычленения из текста существенных признаков ключевого понятия

Влияние травления теллурида кадмия на качество поверхности эпитаксиальных структур

The etching of wafers of cadmium telluride in aqueous and nonaqueous solutions before the epitaxial process of building structures CdxHg1-xTe and its influence on the surface quality of epitaxial layers. As the etchants investigated 2—20 % solution of bromine in isobutyl alcohol, 5 % solution of bromine in methanol, dimethylsulfoxide, ethylene glycol, solutions of bromine in hydrobromic acid and mixed with glycerin, a saturated solution of potassium dichromate in sulfuric acid. The speed of etching was varied from 0.2 to 9 µm/min. Polishing Set nature of the etching substrate of cadmium telluride in 5 % solution of bromine in i-butanol, the dissolution process is diffusion in nature and is limited by the mass transfer of the reactants in the temperature range of 10—60 °C, depending on the concentration of bromine and the viscosity of the solution. Studied the morphology and surface finish of epitaxial layers of CdxHg1-xTe, depending on the method of etching the original substrate. Found the optimal compositions of etchants for precipitaciones processing of obtaining structures with a height of asperities of the surface at 0.1 atm.Исследовано травление подложек теллурида кадмия в водных и неводных растворах перед процессом эпитаксиального наращивания структур CdxHg1-xTe и его влияние на качество поверхности эпитаксиальных слоев. В качестве травителей использовали 2—20%-ные растворы брома в изобутиловом спирте, 5%-ные растворы брома в метаноле, диметилсульфоксиде, этиленгликоле, растворы брома в бромистоводородной кислоте и смеси с глицерином, насыщенный раствор бихромата калия в серной кислоте.Скорости травления изменялись от 0,2 до 9 мкм/мин. Установлен полирующий характер травления подложек теллурида кадмия в 5%-ном растворе брома в изобутаноле. Процесс растворения носит диффузионный характер, лимитирован массопереносом реагентов в интервале температур 10—60 °С и зависит от концентрации брома и вязкости раствора.Исследованы морфология и высота микронеровностей эпитаксиальных слоев CdxHg1-xTe в зависимости от способа травления исходной подложки. Найдены оптимальные составы травителей для предэпитаксиальной обработки с целью получения структур с высотой микронеровностей поверхности на уровне 0,1 мкм

Microarray Immunoassay Tests for Simultaneous Detection of Five Botulinum Toxins by Phosphorescence Analysis (PHOSPHAN)

Combination of multiplex microarray immunoassay tests and luminescent nanoparticle tags is considered as a promising approach to the development of highly sensitive, specific, and rapid methods of causative agent detection. Objective of this study was to develop and compare the sensitivity of the tests for simultaneous detection of five botulinic toxins (A,B,C,E,F) applying multiplex phosphorescence analysis (PHOSPHAN) using standard (Pt coproporphyrin tag-based) and modified (europium containing nanoparticles) systems of phosphorescent signal registration. Materials and methods. PHOSPHAN assay was performed in standard 96 well microplate. The toxoids added to the wells interacted with monospecific and polyvalent immunoglobulins printed as tiny spots on the bottom of each well, and with a mixture of the same antibodies conjugated to biotin. Analyzed anatoxin concentration range – 0.005 to 100 ng/ml. The reaction was manifested by streptavidin conjugated to either Pt coproporphyrin, or the luminescent nanoparticles. The luminescence of both tags was recorded in time-resolved mode by Biochip Analyzer. The limit of detection corresponded to a minimum toxoid concentration, at which the P/N ratio was equal or exceeded 2, while the number of such samples (in a series of 10-30 experiments) was no less than 50%. Results and conclusions. Both multiplex tests provided for simultaneous group-specific detection of five botulinum toxins with the option of type-specific (A, B, E) identification. No cross-reactivity was revealed. The use of phosphorescent nanoparticles allowed for the increase in detection sensitivity by an order of magnitude, up to 10 pg/ml. The tests developed could be recommended for specific detection and identification of botulinum toxins in clinical, environmental, and food samples

Диаграммы «Рыбьи кости»

Current paper is devoted to the Fish bones diagrams — one of the modern graphic tools of data recording and visual representation. We demonstrate its advantages in comparison with traditional (linear) way of data recording.Предлагаемая статья посвящена одному из современных графических инструментов визуального представления и записи информации — диаграммам «Рыбьи кости». Демонстрируются их преимущества перед традиционным (линейным) способом записи