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Rebhi R.,University of Burgundy | Mathey P.,University of Burgundy | Jauslin H.-R.,University of Burgundy | Sturman B.,Institute of Automation and Electrometry
Journal of the Optical Society of America B: Optical Physics | Year: 2010

We show analytically and numerically that the unusual photorefractive nonlinear response of Sn2P2S6 crystals leads to a variety of new features of coherent optical oscillation. In addition to the explanation of the known peculiarities, new features are predicted. © 2010 Optical Society of America. Source

Sun Y.-P.,Shandong Normal University | Sun Y.-P.,KTH Royal Institute of Technology | Wang C.-K.,Shandong Normal University | Wang C.-K.,KTH Royal Institute of Technology | And 2 more authors.
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2010

The energy of the photoelectron experiences a red or blue Doppler shift when the molecule recedes from the detector or approaches him. This results in a broadening of the photoelectron line due to the translational thermal motion. However, the molecules also have rotational degrees of freedom and we show that the translational Doppler effect has its rotational counterpart. This rotational Doppler effect leads to an additional broadening of the spectral line of the same magnitude as the Doppler broadening caused by translational thermal motion. The rotational Doppler broadening as well as the rotational recoil broadening is sensitive to the molecular orbital from which the photoelectron is ejected. This broadening should be taken into account in analysis of x-ray photoemission spectra of super-high resolution and it can be directly observed using x-ray pump-probe spectroscopy. © 2010 The American Physical Society. Source

Steigerwald H.,University of Bonn | Lilienblum M.,University of Bonn | Von Cube F.,University of Bonn | Ying Y.J.,University of Southampton | And 5 more authors.
Physical Review B - Condensed Matter and Materials Physics | Year: 2010

Short-term exposure of the +z face of LiNbO3 crystals to focused UV laser light leads to persistent inhibition of ferroelectric domain reversal at the irradiated area, a phenomenon referred to as "poling inhibition." Different types of crystals (stoichiometric, congruent, or Mg-doped ones) are exposed, creating the so-called "latent state" and domain growth during subsequent electric-field poling is visualized. The latent state is robust against thermal annealing up to 250°C and uniform illumination. With the tip of a scanning force microscope the coercive field is mapped, showing not only the expected resistance against domain reversal in the UV-irradiated region but also easier poling adjacent to the UV-irradiated section. These results and theoretical estimates point to the following mechanism of poling inhibition: the UV light-induced heating results in a local reduction of the lithium concentration, via thermodiffusion. The required charge compensation is provided by UV-excited free electrons/holes. After cooling, the lithium ions become immobile, and the reduced lithium concentration causes a strong local increase in the coercive field in the exposed area, while the increased Li concentration next to this area reduces the coercive field. © 2010 The American Physical Society. Source

Miron C.,Synchrotron Soleil | Kimberg V.,Synchrotron Soleil | Morin P.,Synchrotron Soleil | Nicolas C.,Synchrotron Soleil | And 4 more authors.
Physical Review Letters | Year: 2010

Based on angularly and vibrationally resolved electron spectroscopy measurements in acetylene, we report the first observation of anomalously strong vibrational anisotropy of resonant Auger scattering through the C 1s→π* excited state. We provide a theoretical model explaining the new phenomenon by three coexisting interference effects: (i) interference between resonant and direct photoionization channels, (ii) interference of the scattering channels through the core-excited bending states with orthogonal orientation of the molecular orbitals, (iii) scattering through two wells of the double-well bending mode potential. The interplay of nuclear and electronic motions offers in this case a new type of nuclear wave packet interferometry sensitive to the anisotropy of nuclear dynamics: whether which-path information is available or not depends on the final vibrational state serving for path selection. Source

Novikov Yu.N.,RAS Semiconductor Physics Institute | Vishnyakov A.V.,RAS Semiconductor Physics Institute | Gritsenko V.A.,RAS Semiconductor Physics Institute | Nasyrov K.A.,Institute of Automation and Electrometry | Wong H.,City University of Hong Kong
Microelectronics Reliability | Year: 2010

The charge transport mechanism in amorphous alumina, Al2O3, is investigated both theoretically and experimentally. We found that the experimental current-field-temperature dependencies can hardly be understood based on the commonly used Frenkel effect or the thermally-assisted tunneling model. Instead, we suggest that the charge transport in Al2O3 is related to the ionization of the deep trap by multiphonon tunneling. Excellent agreements between the predicted, the measured data were obtained by using the proposed multiphoton model with the following values of trapping parameters: thermal ionization energy of 1.5 eV, optical ionization energy of 3.0 eV, phonon energy of 0.05 eV, electron effective mass of 0.4me. The density of electron trap and electron capture cross-section of neutral traps are 2 × 1020 cm-3 and 5 × 10-15 cm2, respectively. © 2009 Elsevier Ltd. All rights reserved. Source

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