Acta Physica Slovaca 53(2003)

E. Pincik, H. Kobayashi, J. Mullerova, K. Gmucova, M. Jergel, R.~Brunner, M.~Zeman, M.~Zahoran
On optical, electrical and structural properties of amorphous silicon based semiconductor
Acta Physica Slovaca 53, 267 (2003)
Abstract: The paper deals with structural and electrical properties of original, ion beam, and plasma exposed hydrogenated amorphous silicon (aSi:H) surface. The aSi:H semiconductor forms the intrinsic layer in amorphous silicon solar cells whose performance depends on the defect distribution, particularly on the density of dangling bonds. Devicequality intrinsic aSi:H layer of approx. 1~$\mu $m thickness was deposited on ntype Si(100) oriented crystals in 13,56~MHz rf excited parallel plate plasma enhanced chemical vapor deposition system. Two types of surface exposures were made: by oxygen and argon plasmas. The Ar plasmadamaged surfaces were covered by an oxide layer prepared by \textit{insitu} exposure to pure oxygen atmosphere. In all cases, an uppermost very thin oxide overlayer of 510~nm thickness was formed, thicker than the native oxide formed after the PECVD of the amorphous layer. The optical and structural properties of original and damaged surfaces were investigated by reflectance spectroscopy and Xray diffraction at grazing incidence, respectively. An important transformation of structural properties of a{\}Si:H~ on Si(100) was investigated via the evolution of diffraction pattern around 2$\Theta $~=~28.5\r{ }. Electrical properties were determined by the charge version of deep level transient spectroscopy, CV and IV measurements. Bias annealing procedures lead to the a MIS structure without deep states at the interface. The results obtained are compared with these measured on ion beam exposed aSi:H surfaces [V. N\'{a}da\v{z}dy, R. Durn\'{y}, E. Pin\v{c}\'{\i}k, Phys. Rev. Letters \textbf{78}; 1102 (1997)].

S.B. Faruque
Relativistic periastron shift of a particle in Kerr field: A particular casestudy
Acta Physica Slovaca 53, 279 (2003)
Abstract: This letter presents a calculation of periastron shift in an astrophysical binary in which a nonspinning body moves in a slightly deformed circle round a slowly spinning central body. The equation of motion followed in the calculation was derived earlier by Faruque using relativistic effective onebody dynamics. The results show a clear dependence of periastron shift on magnitude as well as on direction of spin and orbital angular momentum of the central body and the orbiter, respectively, and this dependence is in accord with previous results found by a different procedure by other authors.

A. Grudka, A. Wojcik
Measurement of the overlap between quantum states with the use of coherently addressed teleportation
Acta Physica Slovaca 53, 285 (2003)
Abstract: We will show how to project twophoton polarization states onto symmetric and antisymmetric subspaces of Hilbert space with the use of linear optics and postselection only. It enables to measure the overlap between photon polarization states. Our scheme is based on quantum teleportation and succeeds with the probability of $1 \mathord{\left/ {\vphantom {1 8}} \right. \kern\nulldelimiterspace} 8$.

A. GutierrezRodriguez, M. A. HernandezRuiz
Bounding the $\nu_{\tau}$ magnetic moment from the process $e^{+}e^{}\rightarrow \nu \bar \nu \gamma$ in a leftright symmetric mode
Acta Physica Slovaca 53, 293 (2003)
Abstract: A bound on the $\nu_{\tau}$ magnetic moment is calculated through the reaction $e^{+}e^{}\rightarrow \nu \bar \nu \gamma$ at the $Z_1$pole, and in the framework of a leftright symmetric model at LEP energies. We find that the bound is almost independent of the mixing angle $\phi$ of the model in the allowed experimental range for this parameter.

D. I. Salamov, A.Kucukbursa, I. Maras, H. A. Aygor, T.Babacan, H. Bircan
Calculation of the log(ft) values for the allowed GamowTeller transitions in deformed nuclei using the basis of WoodsSaxon wave function
Acta Physica Slovaca 53, 307 (2003)
Abstract: The present study investigates the log(ft) values of the allowed $\beta^{\pm}$ decay between oddA deformed nuclei in the atomic mass regions of $125\leq A\leq131$ and $159\leq A\leq181$. Single particle energies and wave functions have been calculated with a deformed WoodsSaxon potential. Calculations have been performed within the framework of a protonneutron quasiparticle random phase approximation (QRPA), including the schematic residual spinisospin interaction between nucleons in the particlehole and particleparticle channels. It has been seen that the results obtained by using the values for the fixed particlehole and particleparticle interaction strengths, $\chi^{ph}_{GT}=5.2/A^{0.7}$ $MeV$ and $\chi^{pp}_{GT}=0.58/A^{0.7}$ $MeV$, have good agreement with the experimental observations.

I.N.Askerzade
Temperature dependence of the London penetration depth of YNi$_{2}$B$_{2}$C borocarbids using twoband GinzburgLandau theory
Acta Physica Slovaca 53, 321 (2003)
Abstract: Temperature dependence of London penetration depth of nonmagnetic borocarbides YNi$_{2}$B$_{2}$C is studied in the framework twoband GinzburgLandau theory. Its temperature dependence is nonlinear near T$_{c}$. The strength of the nonlinearity is mainly dependent on the interaction coupling between the order parameters of two separate bands. In addition, the intergradient interaction as well as the ratio of effective masses of two separate bands was also found to be important in determining its temperature dependence. The results of the calculations are in good agreement with the experimental data for bulk YNi$_{2}$B$_{2}$C.

R. Bucik, K. Kudela
On mass in $4\pi$ solid angle around song CsI scintillator aboard coronasI satellite
Acta Physica Slovaca 53, 329 (2003)
Abstract: The complex geometric setup around the SONG CsI scintillator aboard the CORONASI satellite has been modelled, to evaluate the mass thickness passed through by the cosmic ray particle striking the detector. The analytic functional form giving the amount of matter traversed in absorbers for an arbitrary incident directions is present. The population mean and variance of the mass thickness are estimated by random sampling of the uniformly distributed particle trajectories in the several solid angles.
