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Papers by jhon jairo TORRES a

Theoretical Chemistry Accounts, 2010

A time-dependent theoretical method is used to describe a UV pump–UV probe strategy to trace, at ... more A time-dependent theoretical method is used to describe a UV pump–UV probe strategy to trace, at a femtosecond time scale, the motion of vibrational wave packets created in excited states of the hydrogen molecule by measuring single ionization probabilities. We use a spectral method to solve the time-dependent Schrödinger equation in full dimensionality, including correlation and all electronic and vibrational

Physical Review Letters, 2010

Physical Review A, 2010

Using a novel split-mirror setup attached to a Reaction Microscope at the Free electron LASer in ... more Using a novel split-mirror setup attached to a Reaction Microscope at the Free electron LASer in Hamburg (FLASH) we demonstrate an XUV-pump-XUV-probe

Physical Review A, 2009

Photoelectron angular distributions from fixed-in-space H 2 molecules exposed to ultrashort xuv l... more Photoelectron angular distributions from fixed-in-space H 2 molecules exposed to ultrashort xuv laser pulses have been evaluated. The theoretical method is based on the solution of the time-dependent Schrödinger equation in a basis of stationary states that include all electronic and vibrational degrees of freedom. Asymmetric angular distributions are observed as a consequence of the delayed ionization from the H 2 doubly excited states, which induces interferences between gerade and ungerade ionization channels. The analysis of this asymmetry as a function of pulse duration can provide an estimate of the corresponding autoionization widths.

Journal of Physics B: Atomic, Molecular and Optical Physics, 2009

A theoretical study of two-photon ionization of H2 by low-intensity ultrashort xuv laser pulses i... more A theoretical study of two-photon ionization of H2 by low-intensity ultrashort xuv laser pulses is reported. The method is based on the solution of the time-dependent Schrödinger equation in a basis of stationary molecular vibronic states which include all electronic and vibrational degrees of freedom. In contrast with previous work, the \mathcal {Q}_1 doubly excited states, which also contribute to

Journal of Physics: Conference Series, 2009

Journal of Physics: Conference Series, 2012

IEEE Journal of Selected Topics in Quantum Electronics, 2012

ABSTRACT Synopsis A method to compute angular distributions for electrons ejected from fixed-in-s... more ABSTRACT Synopsis A method to compute angular distributions for electrons ejected from fixed-in-space molecular hydrogen when exposed to ultrashort xuv laser pulses is proposed based on the ab initio solution of the time-dependent Schrödinger equation. This method allows for a temporal picture of the origin of the asymmetry in the electron angular ejection that arise due to the interference of the two symmetric dissociative ionization channels (1sσg and 2pσu) in which molecular autoionization states decay after photon absorption. The recent arrival of COLTRIMS reaction microscopes [1] allows for kinematically com-plete experiments in which the momentum of all ejected photofragments is measured in coinci-dence after the breakup caused by a laser pulse. For the dissociative photoionization of molecular hydrogen (H 2 +¯ hω →H + +H+ e −), COLTRIMS gives access to measure proton kinetic energy distributions (KEDs) and photoelectron angu-lar distributions (PADs) associated to a given molecular orientation with respect to the laser polarization direction. This technique is abel to detect the direction along the molecular axis in which the proton H + is emitted. This means that by detecting the localization of the ejected H + , COLTRIMS does not respect the inversion symmetry of the molecule. To satisfy the condi-tions imposed by the experiment, the aymptotic behaviour of the molecular wavefunction must be modified, in particular when two ionization channels (for instance H + 2 1sσ g and 2pσ u) are degenerated at R→ ∞. In our time-dependent method [2], the H 2 wavefunction is expanded in terms of vibronic eigenstates including the con-tinuum for the two H + 2 ionization channels 1sσ g and 2pσ u . To satisfy the localization condition for the proton emission, the final wavepacket at t → ∞ (long after the laser pulse of duration T is ended) must be projected onto the correct asymptotic function which results into a entan-glement of the amplitudes coming from 1sσ g and 2pσ u ionization channels and ultimately produc-ing asymmetries in the PADs with respect to nu-clei inversion. Figure 1 shows proton KEDs and PADs for pro-tons emitted at 90 0 with respect to the laser po-larization vector for some proton KEDs. The symmetry breaking of PADs emerges along the pulse duration for proton KEDs at ∼ 4 eV where the 1sσ g and 2pσ u contributions interfere, in agreement with stationary results [3].

En el siguiente documento se presenta un breve análisis de la influencia que han tenido los grupo... more En el siguiente documento se presenta un breve análisis de la influencia que han tenido los grupos paramilitares en Colombia en cuanto al desarrollo sostenible y el futuro que se esperara tras la firma de los acuerdos de paz, también se hace el análisis si con la implementación del desarrollo sostenible se le puede dar fin a las problemáticas sociales, ambientales y económicas que aquejan al mundo, además se habla de la importancia de la educación para el desarrollo sostenible y los retos que esta enfrenta. Por ultimo se hace un análisis del camino de Colombia para alcanzar el DS y considerase un país desarrollado.

Parafraseando algunos autores Pages (1994) menciona que la didáctica ha sido considerada tradicio... more Parafraseando algunos autores Pages (1994) menciona que la didáctica ha sido considerada tradicionalmente una rama de la pedagogía dedicada al estudio del proceso de instrucción y de la educación en clase. Así mismo Pagés afirma que el nacimiento y el crecimiento de las didácticas especiales arranca de la decisión de incluir y priorizar en los procesos de enseñanza y aprendizaje el contenido de unos saberes concretos. En opinión de Johsua y Dupin (1993). La finalidad de la didáctica de la historia y las ciencias sociales consiste, por tanto, en analizar las prácticas de enseñanza, la realidad de la enseñanza de la historia y las otras ciencias sociales, sus finalidades o propósitos, sus contenidos y sus métodos, para detectar y explicar sus problemas, buscarles soluciones y actuar para transformar y mejorar la práctica de la enseñanza y los aprendizajes-