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Zürich, Switzerland

Burdzinski G.,Adam Mickiewicz University | Sliwa M.,University of Lille Nord de France | Zhang Y.,Massachusetts Institute of Technology | Delbaere S.,University of Lille Nord de France | And 2 more authors.
Photochemical and Photobiological Sciences | Year: 2013

Photochemistry of 4-phenyl-1,2,3-thiadiazole (PT) and 4,5-diphenyl-1,2,3- thiadiazole (DPT) in solution was studied at room temperature using UV-vis and IR transient absorption spectroscopies (λex = 266 nm). Ultrafast techniques show a very fast rise (<0.3 ps) of thiirene and thioketene species, formed from 1,2,3-thiadiazoles in the singlet excited state. The remarkable unimolecular stability of thiirenes in solution is observed. On a millisecond time scale thiirenes with phenyl substituents undergo an intermolecular reaction (dimerization of thiirene-thioketene complexes) leading to 1,3-dithiole derivatives. © 2013 The Royal Society of Chemistry and Owner Societies.

Bezchastnov V.G.,Physikalisch Chemisches Institute | Bezchastnov V.G.,RAS Ioffe Physical - Technical Institute | Pernpointner M.,Physikalisch Chemisches Institute | Schmelcher P.,Physikalisch Chemisches Institute | And 2 more authors.
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2010

We present all-electron relativistic studies of the polarizability properties of the Xe dimer. The studies rely on finite-field calculations of the dimer energies obtained by ab initio methods including electron correlations. An extended set of basis functions is designed in order to ensure a high accuracy of the calculations. Particular attention is paid to the analysis of the nonadditivity and anisotropy of the polarizability of the dimer. It is found that the polarizability of the dimer relative to that of the atoms can be accurately described analytically, at least for internuclear distances around and larger than the equilibrium distance of the dimer. © 2010 The American Physical Society.

Inarrea M.,University of La Rioja | Salas J.P.,University of La Rioja | Gonzalez-Ferez R.,University of Granada | Schmelcher P.,Physikalisch Chemisches Institute | Schmelcher P.,University of Heidelberg
Physics Letters, Section A: General, Atomic and Solid State Physics | Year: 2010

We study the classical dynamics of a polar diatomic molecule in the presence of a strong static homogeneous electric field. Our full rovibrational investigation includes the interaction with the field due to the permanent electric dipole moment and the polarizability of the molecule. Using the LiCs molecule as a prototype, we explore the stability of the equilibrium points and their bifurcations as the field strength is increased. The phase space structure and its dependence on the energy and field strength are analyzed in detail. We demonstrate that depending on the field strength and on the energy, the phase space is characterized either by regular features or by small stochastic layers of chaotic motion. © 2009 Elsevier B.V. All rights reserved.

Pont F.M.,National University of Cordoba | Bande A.,Helmholtz Center Berlin | Bande A.,Physikalisch Chemisches Institute | Cederbaum L.S.,Physikalisch Chemisches Institute
Journal of Physics Condensed Matter | Year: 2016

We recently predicted that the interatomic Coulombic electron capture (ICEC) process, a long-range electron correlation driven capture process, is achievable in gated double quantum dots (DQDs). In ICEC an incoming electron is captured by one quantum dot (QD) and the excess energy is used to remove an electron from the neighboring QD. In this work we present systematic full three-dimensional electron dynamics calculations in quasi-one dimensional model potentials that allow for a detailed understanding of the connection between the DQD geometry and the reaction probability for the ICEC process. We derive an effective one-dimensional approach and show that its results compare very well with those obtained using the full three-dimensional calculations. This approach substantially reduces the computation times. The investigation of the electronic structure for various DQD geometries for which the ICEC process can take place clarify the origin of its remarkably high probability in the presence of two-electron resonances. © 2016 IOP Publishing Ltd. All rights reserved.

Rehbinder J.,Physikalisch Chemisches Institute | Rehbinder J.,Ecole Polytechnique - Palaiseau | Bruckner L.,Physikalisch Chemisches Institute | Wipfler A.,Physikalisch Chemisches Institute | And 2 more authors.
Optics Express | Year: 2014

We demonstrate the use of shaped 10 fs pulses for multimodal microscopy. The combination of a broadband oscillator and a pulse shaper provides a flexible light source that can be optimized for various nonlinear effects produced in the sample, either for signal intensity or for selectivity. While the highest nonlinear generation efficiency is achieved with the shortest pulses, more complex waveforms address specific transitions in the sample for better contrast. This is shown experimentally with the imaging of a moss leaf and of human skin biopsies using coherent anti-Stokes Raman scattering, two-photon fluorescence and second harmonic generation signals. ©2014 Optical Society of America

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