Laboratoire de Physique Théorique
Toulouse - UMR 5152

Aim and objectives

Following the tradition of the previous successful six meetings (2009-2014), the Theory Days workshop aims at stimulating constructive discussions, collaborations, and knowledge exchange among a selected group of theoreticians. This year the workshop will be dedicated to various methods and numerical treatments of the dynamics of irradiated nanosystems.

A molecule, a cluster or a solid, excited by a strong external electromagnetic field, as a laser pulse or a swift charged projectile, can respond in several ways but the first agents that react are the electrons of the system. They can reach excited states or can even be expelled from the system, leading to electronic emission. The theoretical and numerical description of the dynamics of ionization constitutes a growing and challenging field in molecular and cluster physics, especially regarding the numerous experimental measurements of energy- and/or angle-resolved distributions of emitted electrons. One can also consider high harmonic generation (HHG) in clusters and molecules with their many potential applications, in particular in attosecond science, which open the possibility to explore molecules at time and spatial scales not attainable before. The commonly accepted mechanism of HHG consists in electron emission from a system irradiated in the infrared domain, then an excursion of the emitted electrons away from the parent molecule, and finally recombination of these electrons with the remaining ones in the molecule. There is however very few fully microscopic calculations in real time and real space of such a recombination process, a major hindrance being precisely the description of the possibly very large excursion of emitted electrons. Another important issue of irradiation dynamics is connected to the degradation of solvated biomolecules by low energy electrons. Indeed it has been shown experimentally that the low energy electrons which are produced by a strong electromagnetic perturbation in solvated DNA can interact or recombine to other molecular species from the environment of the primary target, and finally lead to DNA break-up. This mechanism is known as the dissociative electron attachment and is widely studied experimentally. However it is still poorly described microscopically with a proper account of environment effects, as it remains well beyond present day computational capabilities.

We plan to gather people from various groups working in this domain, mostly in western Europe. The workshop is intended to be a working forum, thus rather informal. The format will consist in a series of long detailed talks, typically 40 mn talk + 10 mn for questions, focusing in particular on ongoing problems and open ends. Some free time will furthermore be reserved for collective discussions. We thus urge participants to prepare their talks in this spirit. Ultimately a most efficient organization would consist in having a limited number of talks per representative group in order to avoid doublings.

If a consensus is reached during the workshop it would be highly profitable to envision a sequel to this workshop in order to possibly establish, at best collaborative links between the various groups with possible exchange of researchers and students, at worst an ongoing follow up of progress in the field.

Scientific program