Accueil > Séminaires > Année 2024
Intrinsic Optical Signatures of Layered Materials : Case Studies of Hexagonal Boron Nitride and Black Phosphorus
Over the past two decades, the growing family of 2D materials has attracted considerable attention in the physics community, offering new perspectives for electronic and optoelectronic applications. In this talk, the interplay between structural and optical signatures will be examined for two particular members of the family : hexagonal boron nitride and black phosphorus. (…)
Spectroscopie de rotation et cinétique des collisions réactives de systèmes moléculaires en milieu dilué
L’étude de la structure moléculaire et des propriétés physiques et chimiques intrinsèques des molécules et des complexes moléculaires doit se faire en premier lieu de manière isolée, au moyen de systèmes moléculaires simples et dans des milieux dilués. Dans la première partie du séminaire, je présenterai la technique de la spectroscopie de rotation, qui est largement utilisée pour (…)
Le séminaire aura lieu en VISIOCONFERENCE : demander le lien à seminaires.ismo@universite-paris-saclay.frrouge]
Physical and chemical processes in molecular ices in the interstellar medium
Molecular ices play a central role in the evolution of the interstellar medium, which is commonly described as the space between stars. These ices form on the surface of sub-micrometric refractory solids that populates the cold regions (T < 150 K) and they are mainly composed of H2O, followed by (…)
Simulating high-pressure surface reactions with molecular beams
Using a reactive molecular beam with high kinetic energy (Ekin) it is possible to speed gas-surface reactions involving high activation barriers (Eact), which would require elevated pressures (P0) if a random, Maxwell-Boltzmann gas is used. By simply computing the number of molecules that overcome the activation barrier in a random gas at P0 and in a molecular beam at Ekin=Eact, we establish a P0(Ekin) equivalence curve. (…)
Clocking the tunneling time in strong-field ionization
When a quantum particle undergoes tunneling, the time spent under the barrier, referred to as the tunneling time, is subject to several debated questions regarding both its definition and its measurability [1,2]. In particular, the measurement of the tunneling times in the context of strong-field ionization [3] is still controversial [4] and the latest conclusions remain in conflict with the results from so-called Larmor clock (…)
Systèmes modèles pour la simulation de processus non linéaires ultrarapides
Comment suivre un processus dépendant du temps lorsque celui ci se déroule à des échelles de temps "ultrarapides" (femtoseconde ou subfemtoseconde) ? Comment modéliser de tels processus, et comment les interpréter ? Dans ce séminaire je donnerai quelques pistes de réponse à partir de quelques exemples issus de mes travaux : ionisation tunnel, génération d’harmonique d’ordres élevés, déclin Auger.
Using X-ray action spectroscopy to probe gas-phase biomolecular ions
Proton transfer is a fundamental charge transfer process in chemistry, and it is particularly important for biological molecules, since they usually contain basic groups. Therefore, in order to study charge dynamics in isolated biomolecules, it is crucial to determine the location of protons. Moreover, water plays an important role in the structure and properties of biomolecules. Already a single water molecule can (…)