Marco Ruberti, Imperial College, London, UK“Theoretical modelling of attosecond pump-probe spectroscopy for quantum-coherent electron dynamics”Chair: Ladislau Nagy (Babes-Bolyai University, RO) Abstract:
Marco Ruberti, Imperial College, London, UK
“Theoretical modelling of attosecond pump-probe spectroscopy for quantum-coherent electron dynamics”
Chair: Ladislau Nagy (Babes-Bolyai University, RO)
The advent of attosecond laser pulses generated by high‐harmonic generation and X-ray free electron lasers has created unique opportunities for studying the very first few femtoseconds of the many-electron dynamics triggered by photoionization in atoms, molecules, and condensed matter [1‐3].
Two fundamental quantum-mechanical concepts characterize these many-electron dynamics: quantum coherence and quantum entanglement. For example, quantum electronic coherence in photoionized molecules, arising at the attosecond and persisting at the femtosecond time scales, underpins the few-femtosecond charge dynamics (hole migration) and therefore also the ensuing photochemical transformation of matter.
Here I will present the new theoretical approaches that I recently developed to describe, from first principles, the quantum-coherent many-electron dynamics triggered by ionization of atomic and molecular systems by arbitrary laser fields, the time-dependent (TD) B-spline algebraic diagrammatic construction (ADC) method  and its restricted correlation space (RCS)-ADC extension . The TD B-spline RCS-ADC method extends the ab initio ADC approach, originally developed to describe bound state dynamics , to the realm of ultrafast ionization dynamics.
I will describe how the new methodology allows us to accurately predict the mixed state of the ionized system prepared by attosecond and strong-field ionization of a molecular system . I will also present recent applications of the TD B-spline RCS-ADC method to the simulation of complete numerical pump-probe experiments of ultrafast dynamics in molecular systems [8,9].
Finally, I will report results on the simulation of a recent experiment at FLASH that, by using few-femtosecond XFEL pulses in a X-ray pump – X-ray probe measurement based on X-ray electron emission spectroscopy (XPS), captured coherent, inner-valence electron hole dynamics with ~ 20 fs periodicity in molecular glycine .
 G. Sansone, et al. Nature 465, 763 (2010).
 E. Goulielmakis, et al. Nature 466, 739 (2010).
 F. Calegari, et al. Science 346, 336 (2014).
 M. Ruberti, P. Decleva and V. Averbukh, Phys. Chem. Chem. Phys. 20, 8311-8325 (2018); V. Averbukh and M. Ruberti, “First-principles Many-electron Dynamics Using the B-spline Algebraic Diagrammatic Construction Approach” in “Attosecond Molecular Dynamics”, edited by Marc J. J. Vrakking and Frank Lepine, RSC Theoretical and Computational Chemistry series 13, 68-102 (2018).
 M. Ruberti, J. Chem. Theory Comput. 15, 6, 3635-3653 (2019).
 J. Schirmer, L. S. Cederbaum, and O. Walter, Phys. Rev. A 28, 1237 (1983) M. Ruberti, Phys. Chem. Chem. Phys. 21, 17584-17604 (2019).
 M. Ruberti, P. Decleva and V. Averbukh, J. Chem. Theory Comput. 14, 10, 4991-5000 (2018).
 M. Ruberti, Faraday Discussions, (2020), DOI: 10.1039/D0FD00104J.
To register for this event, please, follow this link: https://brightelm.eventsair.com/attochem-webinar-series-2021/reg/Site/Register
If you have already registered but have not received the link to the webinar, please contact: Attochem@brightelm.co.uk
(Wednesday) 15:00 - 16:00
Deprecated: Theme without comments.php is deprecated since version 3.0.0 with no alternative available. Please include a comments.php template in your theme. in /var/www/html/attochem/wp-includes/functions.php on line 5283