[Todos] Seminario Conjunto en el DF - A. Abedi - E. Khosravi: Lunes 18/12, 14hs, Aula Seminario, 2do piso, Pab. I

[Johanna Ildemar Fuks]

Hola!

Se postpone el seminario de A. Abedi y E. Khosravi para otro dia de  
esta semana. Fecha y hora a confirmar en el proximo email!

Saludos,
Johanna


Quoting Augusto Roncaglia <augusto en df.uba.ar>:

> SEMINARIO CONJUNTO EN EL DEPARTAMENTO DE FÍSICA EXACTAS - UBA
>
>
>                         En el Aula Seminario, 2do piso, Pab. I,
>
>                         Lunes 18/12, 14hs:
>
>
> 1. *Correlated electron-nuclear dynamics*
>    ALI ABEDI
>    Universidad del Pais Vasco
>
> 2. *The exact potential driving the electron dynamics in enhanced
> ionization of H2+- isotopes effects*
>    ELHAM KHOSRAVI
>    Universidad del Pais Vasco
>
>
>
> *Correlated Electron-Nuclear Dynamics*
>
> The coupling between electronic and nuclear motion plays an important role
> in many fascinating phenomena, such as superconductivity, the process of
> vision, as well as photo-synthesis. There are standard approximations such
> as Ehrenfest dynamics or surface hopping that partially capture the
> non-adiabatic effects. As a first step towards a full ab-initio treatment
> of the coupled electron-nuclear system, we deduce an exact factorization of
> the complete wavefunction into a purely nuclear part and a many-electron
> wavefunction which parametrically depends on the nuclear configuration. We
> derive formally exact equations of motion for the nuclear and electronic
> wavefunctions [1-3]. These exact equations lead to a rigorous definition of
> time-dependent potential energy surfaces (TDPES) as well as time-dependent
> geometric phases. We analyze features of the TDPES in two topically
> demanding situations:
> molecules in strong fields [1-3] and splitting of a nuclear wave-packet at
> avoided crossings [5] Born-Oppenheimer potential energy surfaces. In
> addition, by studying a numerically exactly solvable model we demonstrate
> that the molecular Berry phase and the corresponding non-analyticity in the
> electronic Born-Oppenheimer wavefunction is, in general, not a true
> topological feature of the exact solution of the full electron-nuclear
> Schroedinger equation and only appear in the limit of infinite nuclear mass
> [4].
>
> Finally, we present a novel mixed quantum-classical approach [5] to the
> coupled electron-nuclear dynamics based on the equations of motion for the
> electronic and nuclear subsystems within the exact factorization framework.
> The nuclear equation is a standard Schroedinger equation containing a TDPES
> as well as a time-dependent vector potential. Starting from these
> equations, the correct classical limit of the nuclear dynamics is worked
> out by taking the classical limit of the exact time-dependent Schroedinger
> equation satisfied by the nuclear wave function. The effect of the
> time-dependent scalar and vector potentials, representing the exact
> electronic back-reaction on the nuclear subsystem, is consistently derived
> within the classical approximation. Using a model system, we examine the
> performance of the proposed mixed quantum-classical scheme in comparison
> with exact calculations, in the presence of strong non-adiabatic coupling
> between the electronic and nuclear motion.
>
> References:
> [1] A. Abedi, N. T. Maitra, and E. K. U. Gross, Physical Review Letters 105
> 123002 (2010).
> [2] A. Abedi, N. T. Maitra, and E. K. U. Gross, Journal of Chemical Physics
> 137 22A530 (2012)
> [3] A. Abedi, F. Agostini, Y. Suzuki, E. K. U. Gross, Physical Review
> Letters 110 263001 (2013).
> [4] S. K. Min, A. Abedi, K. S. Kim, and E. K. U. Gross, Physical Review
> Letters 113 263004 (2014).
> [5] A. Abedi, F. Agostini, and E. K. U. Gross, Europhysics Letters 106
> 33001 (2014).
>
>
>
>
> *The exact potential driving the electron dynamics in enhanced ionization
> of H2+- isotopes effects*
>
> The exact potential [1] driving the electron's dynamics [2] in enhanced
> ionization of H2+ can have large contributions arising from dynamical
> electron-
> nuclear correlation, going beyond what any Coulombic-based model can
> provide [3]. This potential is defined via the exact factorization of the
> molecular
> wavefunction that allows the construction of a Schrödinger equation for the
> electronic system, in which the potential contains exactly the effect of
> coupling
> to the nuclear system and any external fields [1,2]. To investigate
> nuclear-mass-
> dependence in enhanced ionization, we study isotopologues of H2+ . We
> decompose the exact potential into components that naturally arise from the
> conditional wavefunction, and also into components arising from the marginal
> electronic wavefunction, and compare the performance of propagation on these
> different components as well as approximate potentials based on the quasi-
> static or Hartree approximation with the exact propagation [4].
>
> References:
> [1]. A. Abedi, N. T. Maitra, and E. K. U. Gross, Phys. Rev. Lett. 105,
> 123002 (2010).
> [2]. Y. Suzuki, A. Abedi, N. T. Maitra, K. Yamashita, and E. K. U.  
> Gross, Phys.
> Rev. A 89, 040501 (2014).
> [3]. E. Khosravi, A. Abedi, and N. T. Maitra, Phys. Rev. Lett. 115, 263002
> (2015)
> [4]. E. Khosravi, A. Abedi, A. Rubio, N. T. Maitra, PCCP, 19 , 8269 (2017)