Full-text resources of PSJD and other databases are now available in the new Library of Science.
Visit https://bibliotekanauki.pl
Preferences help
Polish version English version Language
enabled [disable] Abstract
Number of results

Results found: 5

Number of results on page
first rewind previous Page / 1 next fast forward last

Search results

help Sort By:

help Limit search:
first rewind previous Page / 1 next fast forward last
1
Content available remote

Proposed Experiment with Rydberg Atoms to Study the Influence of Particle Size on Quantum Interference

100%
Gondran M., Božić M., Arsenović D., Gondran A.
Acta Physica Polonica A
|
2007
|
vol. 112
|
issue 5
805-810
EN
We are looking for the answers to some questions which naturally arise when one starts to think about possible influence of the size of a particle on the transmission, diffraction and interference pattern behind an interference grating.
2
Content available remote

Perturbative Solution of Optical Bloch Equations for Analysis of Electromagnetically Induced Absorption

100%
Dimitrijević J., Arsenović D., Jelenković B.
Acta Physica Polonica A
|
2009
|
vol. 116
|
issue 4
468-470
EN
We study phenomenon of electromagnetically induced absorption in the Hanle configuration by solving time-dependent optical Bloch equations for the case of the closed multilevel F_g=1 → F_e=2 transition. Our model gives optical Bloch equations as a non-homogeneous system of ordinary linear differential equations. For weak laser fields (Ω ≪ Γ i.e. Rabi frequency small compared to spontaneous emission rate), a perturbative method to solve linear differential equations can be applied. Perturbative method is realized by solving (in the time-domain) higher-order corrections to the density matrix which in the sum converge to the exact solution of optical Bloch equations. By its form, each successive correction is also system of ordinary linear differential equations which depends on the solution of previous ones. Corrections are partitioned such that odd give corrections to optical coherences, while even give corrections to populations and Zeeman coherences. We present numerical results for the behavior of density matrix elements with successive corrections, and compare them with exact solution of optical Bloch equations. Electromagnetically induced absorption is observed as a 4th and higher (even) correction to populations, when behavior in respect to both time and magnetic field is viewed. Since in our method each correction depends on the solution of previous ones, we can analyze how (through mechanism of transfer of coherences and transfer of populations between Zeeman sublevels) electromagnetically induced absorption is formed. We also discuss qualitative differences in the behavior (with respect to time) of certain density matrix elements for magnetic fields "inside" and "outside" electromagnetically induced absorption resonance.
3
Content available remote

Structural Characterization and Statistical Properties of Two-Dimensional Granular Systems During the Compaction

88%
Živković S., Jakšić Z., Arsenović D., Budinski-Petković L., Vrhovac S.
Acta Physica Polonica A
|
2011
|
vol. 120
|
issue 2
246-251
EN
We study the compaction dynamics of frictional hard disks in two dimensions, subjected to vertical shaking, by numerical simulation. Shaking is modeled by a series of vertical expansions of the disk packing, followed by dynamical recompression of the assembly under the action of gravity. The second phase of the shake cycle is based on an efficient event-driven molecular-dynamics algorithm. We analyze the compaction dynamics for various values of the friction coefficient and the coefficient of normal restitution. The granular organization at local level was studied by analyzing the shape factor ξ of the local volumes, associated with a natural way of subdividing the volume into local parts - the Voronoi partition. It gives a clear physical picture of the competition between less and more ordered domains of particles during the compaction. We calculate the distribution of the shape-factor for packings at different stages of the compaction process. We have also investigated a two-dimensional granular medium experimentally. We prepared the granular packings of metallic cylinders of diameters 4, 5, and 6 mm. The distributions of the shape-factor obtained numerically for various tapping intensities are consistent with our experimental results.
4
Content available remote

Effect of Laser Light Ellipticity on Hanle Electromagnetically Induced Absorption Amplitude and Line Width

76%
Dimitrijević J., Grujić Z., Mijailović M., Arsenović D., Panić B., Jelenković B.
Acta Physica Polonica A
|
2007
|
vol. 112
|
issue 5
841-845
EN
Using the ^2S_{1/2} F_g=2→^2P_{3/2} F_e=3 transition in ^{87}Rb, we analyzed the interaction between the arbitrarily polarized laser light and Zeeman sublevels in the Hanle configuration. We studied theoretically and confirmed experimentally that the effect of the laser light polarization on the electromagnetically induced absorption strongly depends on the laser light power. For the same atomic transition, and for single laser light power (3 mW), it was recently shown that electromagnetically induced absorption line widths increase with polarization ellipticity and that electromagnetically induced absorption amplitude has maximum for certain laser light polarization different than linear. Here, we present results for amplitudes and widths of electromagnetically induced absorption for different laser light polarizations and for the laser light power≤ 200μW. It is verified that for small laser light power maximal electromagnetically induced absorption amplitude is for the linear polarization, whereas for larger power maximum of the electromagnetically induced absorption is at higher polarization ellipticity.
5
Content available remote

Dancing Light: Counterpropagating Beams in Photorefractive Crystals

64%
Belić M., Petrović M., Jović D., Strinić A., Arsenović D., Prvanović S., Jovanović R., Petrović N.
Acta Physica Polonica A
|
2007
|
vol. 112
|
issue 5
729-736
EN
A review of work on the dynamical behavior of counterpropagating incoherent laser beams in photorefractive crystals is presented. Numerical study of counterpropagating beams of different type is carried out, in both space and time, using an appropriate theoretical model. The development of patterns in broad hyper-Gaussian counterpropagating beams in saturable Kerr-like media is investigated, by varying the width of beams. Rotational properties of counterpropagating mutually incoherent self-trapped vortex beams in optically induced fixed photonic lattices are also investigated numerically. One of the fundamental quantum mechanical phenomena is observed for the counterpropagating beams in photonic lattices, the tunneling of light from the first to the higher-order bands of the lattice band gap spectrum. The transfer of angular momentum from vortex beams to optically induced photonic lattices is also demonstrated. For the interacting beams it is found that the sum of angular momenta of counterpropagating components is not a conserved quantity, but the difference is. In the fixed lattices there is always a considerable loss of angular momentum.
first rewind previous Page / 1 next fast forward last
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.