Zeros of Rydberg-Rydberg Foster Interactions

Rydberg states of atoms are of great current interest for quantum manipulation of mesoscopic samples of atoms. Long-range Rydberg-Rydberg interactions can inhibit multiple excitations of atoms under the appropriate conditions. These interactions are strongest when resonant collisional processes give rise to long-range C_3/R^3 interactions. We show in this paper that even under resonant conditions C_3 often vanishes so that care is required to realize full dipole blockade in micron-sized atom samples.Comment: 10 pages, 4 figures, submitted to J. Phys.

Electrophysical Properties of Granular Film Alloys Based on Fe and Ag or Au

The experimental results of electrophysical properties of granular film alloys based on Fe and Ag or Au are presented. It is established that the value of the temperature coefficient of resistance depends on the total thickness of the samples and the concentration of magnetic component. The components concentration in the system is shown to affect the formation of the solid solution and the granular film alloy. The optimal concentration value of Fe, in which the thermally stable solid solution forms, is 45 at. %

Quantum Noise Limits for Nonlinear, Phase-Invariant Amplifiers

Any quantum device that amplifies coherent states of a field while preserving their phase generates noise. A nonlinear, phase-invariant amplifier may generate less noise, over a range of input field strengths, than any linear amplifier with the same amplification. We present explicit examples of such nonlinear amplifiers, and derive lower bounds on the noise generated by a nonlinear, phase-invariant quantum amplifier.Comment: RevTeX, 6 pages + 4 figures (included in file; hard copy sent on request

Conditional quantum logic using two atomic qubits

In this paper we propose and analyze a feasible scheme where the detection of a single scattered photon from two trapped atoms or ions performs a conditional unitary operation on two qubits. As examples we consider the preparation of all four Bell states, the reverse operation that is a Bell measurement, and a CNOT gate. We study the effect of atomic motion and multiple scattering, by evaluating Bell inequalities violations, and by calculating the CNOT gate fidelity.Comment: 23 pages, 8 figures in 11 file

Formation of Professional-Pedagogical Culture оf Future Specialists оf Physical Culture аnd Sports Specialties

The results of research showed the need to organize in the institution of higher education conditions and a set of measures aimed at the formation of professional-pedagogical culture of future specialists, which makes it possible to strengthen educational work with them based on the translation of the values of the cultural and sports heritage of the subject of the state, the effective formation of their professionalism and pedagogical culture. The proposed system of professional training of future specialists of physical education and sports on acme-culturological bases directs teachers to improve the quality of training graduates in their future professional activities

Санітарний стан соснових насаджень на рекультивованих землях

The purpose of the research is to determine the sanitary state of pine plantations on reclaimed lands, to identify the influence of biotic and abiotic factors on the changes in the sites and to provide recommendations for improving the biological resistance of pine forests in conditions of natural and man-made impact. The sanitary state of pine plantations created on the reclaimed lands of Yurkivskyi brown coal mine has been analyzed. Plants grow in difficult conditions on displaced, low-power soils with carbonaceous sands. The species composition of the lower tiers of forest phytocoenoses (undergrowth, understore, above ground layer), which is formed in medieval artificial pine plantations of fresh pine sites, indicates the restoration of flora diversity of reclaimed lands through forest amelioration. According to data of 61 circular test plots, which cover typical sites of pine plantations on the area of 141.1 hectares, indices of sanitary state of plantations have been calculated. The analysis of the sanitary index has shown that pine plantations are severely weakened. The weakened pine trees make up 44.7 %, and the sanitary index ranges from 3.01 to 3.41. The state of pine plantations of the V age class is approaching the category of plantations that are drying up with the highest value of the state index of 3.41. Weakening of plantations may cause the spread of fires in the fire danger period, outbreaks of diseases and the spread of anthropomorphs. We have revealed that the most influential factors of the significant deterioration of the sanitary state of pine plantations on the reclaimed lands of the Yurkivskyi brown coal basin are dangerous to the root sponge and the drying of trees as a result of a decrease in the nutrition of plants that reached the disturbed maternal horizon at a depth of more than 40-50 cm. In order to prevent the development of the root sponge, it is recommended to create mixed pine plantations with the introduction of up to 50 % of deciduous, which at the same time will serve as a fire barrier for the spread of grass fires. For the improvement of pine plantations, increasing the reclamation efficiency and eliminating the cells of the root sponge, it is expedient to perform continuous sanitary felling with the subsequent planting of deciduous species.Проаналізовано санітарний стан соснових насаджень, створених на рекультивованих землях Юрківського буровугільного кар'єру. Насадження ростуть у складних умовах на переміщених, малопотужних ґрунтах із вуглистими пісками. За даними 61 кругової пробної площі, які охоплюють типові умови зростання соснових культур на площі 141,1 га, обчислено показники санітарного стану насаджень. Аналіз показника санітарного стану показав, що соснові насадження належать до сильно ослаблених. Ослаблені дерева сосни становлять 44,7 %, а показник санітарного стану змінюється у межах 3,01–3,41. Стан соснових насаджень V класу віку наближається до категорії насаджень, що всихають з найвищою величиною показника стану 3,41. Встановлено, що найвпливовішими чинниками істотного погіршення санітарного стану соснових культур на рекультивованих землях Юрківського буровугільного басейну є ураження кореневою губкою і всихання дерев унаслідок зменшення живлення рослин, які досягли порушеного материнського горизонту на глибині понад 40–50 см. Для запобігання розвитку кореневої губки необхідно створювати мішані культури сосни звичайної з введенням до 50 % листяних порід, які водночас будуть протипожежним бар'єром поширення низових пожеж. Для оздоровлення соснових насаджень, підвищення меліоративної ефективності та ліквідації осередків кореневої губки доцільно проводити суцільні санітарні рубки з подальшим висаджуванням листяних порід

Comparison of Theory and Experiment for a One-Atom Laser in a Regime of Strong Coupling

Our recent paper reports the experimental realization of a one-atom laser in a regime of strong coupling (Ref. [1]). Here we provide the supporting theoretical analysis relevant to the operating regime of our experiment. By way of a simplified four-state model, we investigate the passage from the domain of conventional laser theory into the regime of strong coupling for a single intracavity atom pumped by coherent external fields. The four-state model is also employed to exhibit the vacuum-Rabi splitting and to calculate the optical spectrum. We next extend this model to incorporate the relevant Zeeman hyperfine states as well as a simple description of the pumping processes in the presence of polarization gradients and atomic motion. This extended model is employed to make quantitative comparisons with the measurements of Ref. [1] for the intracavity photon number versus pump strength and for the photon statistics as expressed by the intensity correlation function g2(tau).Comment: 19 pages, 14 figures. Added sections on: scaling properties, vacum-Rabi splitting, and optical spectru