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dr Małgorzata Wiertel

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Pracownia Dydaktyki Fizyki

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pokój: 355
telefon: (081) 537-61-50
e-mail: malgorzata.wiertel@umcs.pl

Specjalność naukowa:

fizyka

Publikacje: Ukryj abstrakty

  1. Taranko, E. Taranko, R. Wiertel, M., Electron transport in the multi-terminal quantum dot system, Optica Applicata, 35(3), 2005, 369-374

    Abstract:
    The time-dependent electron transport through a multi-terminal quantum dot system is studied. External microwave fields with arbitrary amplitudes, phases and frequencies are applied to different parts of the system considered. The dependence of the average current and average differential conductance on different parameters of the external microwave fields is analyzed. Special attention is paid to the photon-electron pump effect observed for some values of the quantum dot system parameters.

  2. Wiertel, M. Taranko, E. Taranko, R., Charge transfer dynamics in atom scattering on atoms adsorbed on metal surface: Effect of electron correlations, Vacuum, 78(2-4), 2005, 325-329

    Abstract:
    The time-dependent Anderson-Newns Hamiltonian with spin- dependent effective atom energy levels calculated within the Hartree-Fock approximation is used to study the occupation numbers of the atom scattered on another atom (adatom) adsorbed on the metal surface. The calculations are performed using the evolution operator approach. The memory effect of the initial spin polarisation of the scattered atoms is analysed for a broad class of parameters characterising the considered system. (c) 2005 Elsevier Ltd. All rights reserved.

  3. Taranko, R. Wiertel, M. Taranko, E., Electron correlation effects in scattering of atom on the atom adsorbed on the metal surface, Vacuum, 74(2), 2004, 207-210

    Abstract:
    The role of Coulomb correlations on the resonant charge transfer in atom scattering on an atom adsorbed on a metal surface has been studied theoretically within the Hartree-Fock approximation and the time-dependent Anderson-Newns model. Using the evolution operator technique the probabilities of the different charge states of the back-scattered atoms were calculated for broad range of parameters. In particular, the effect of the constant or z-dependent (z being the distance of the moving atom from the surface) effective intra-atomic Coulomb correlations was analysed. (C) 2004 Elsevier Ltd. All rights reserved.

  4. Taranko, R. Taranko, E. Wiertel, M., Charge transfer in collisions of atoms with the metal surface: influence of surface adatoms structures, Vacuum, 72(1), 2003, 71-78

    Abstract:
    We have studied the resonant charge transfer between a metal surface with a cluster of impurities on it and a moving atom back-scattered on the surface atom. The calculations of the electron occupancy of the outgoing atom were made within the time-dependent Anderson-Newns model. We have shown that the final electron occupancy of scattered atom depends on arrangements of the impurity atoms and the position of the surface atom on which the moving atom is scattered. (C) 2003 Elsevier Ltd. All rights reserved.

  5. Taranko, R. Taranko, E. Wiertel, M., Effect of an adsorbed atom on resonant charge exchange in atom scattering on metal surfaces, Acta Physica Polonica A, 103(5), 2003, 483-497

    Abstract:
    A simple model describing resonant charge transfer between the free-electron metal surface and an atom colliding with it at some distance from another adsorbed atom is presented. The negative ionization probability of a scattered atom is studied within the time-dependent Anderson-Newns model and the time- evolution operator approach. With appropriate models for the considered system, the ionization probability is shown to oscillate with the distance between the adsorbed atom and the collision point of the scattered atom with the metal surface. These oscillations are results of the indirect interaction between the adsorbed and the scattered atoms due to the coupling of both atoms with the metal energy band.

  6. Wiertel, M. Taranko, E. Taranko, R., Influence of adsorbed atoms on the charge transfer in atom/ion- surface collision, Optica Applicata, 32(3), 2002, 301-305

    Abstract:
    The ionization probability of an atom scattered on the atom adsorbed on a metal surface has been studied theoretically within the time-dependent Anderson-Newns model and the time- evolution operator technique. The influence of different parameters describing the investigated system on the dynamics of the charge transfer between the moving atom and the metal surface with an adsorbed atom has been investigated and the comparison with the results obtained for scattering on a clean metal surface has been made.

  7. Wiertel, M. Taranko, E. Taranko, R., Resonant charge exchange in atom scattering on atoms adsorbed on metal surfaces, Acta Physica Polonica A, 101(6), 2002, 837-855

    Abstract:
    The ionization probability of an atom scattered from an atom adsorbed on a metal surface has been studied theoretically within the time-dependent Anderson-Newns model. The effect of the metal electron density of states, the band filling as well as the relative position of the scattered atom and adsorbed atom energy levels have been considered and the comparison with the results obtained for clean surfaces has been made.

  8. Wiertel, M. Taranko, R. Taranko, E., Charge transfer dynamics in atom-metal surface collisions, Acta Physica Polonica A, 96(6), 1999, 769-783

    Abstract:
    We study the charge exchange in atom-metal collisions in the framework of the generalized time-dependent Anderson-Newns model. The electron correlations and correlated hopping are treated within the mean-field approximation. The resulting one- particle model with an effective spin-dependent atom-surface coupling is used to study the charge transfer in scattering of Na and Li atoms on metal surfaces. It is shown that the effective occupation dependent atom-surface coupling influences mainly the expectation values for producing positive, neutral, and negative particles for small work functions and high atom velocities. It is also shown that the temperature dependence of these expectation values is more visible, especially for magnetic solutions.


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