Research

I study ultra-fast dynamics at the attosecond and femtosecond time scales in atoms and small molecules. In particular I am interested in the highly non-linear processes at the basis of attosecond science, such as high-order harmonic generation (HHG), tunnel ionization or above threshold ionization (ATI). I also study attosecond spectroscopic tools such as the reconstruction of attosecond beating by interference of two-photon transitions (RABBITT), high-order harmonic spectroscopy (HHS) and attosecond transient absorption spectroscopy (ATAS). As a theoretician my work is divided into investigating new physical and chemical processes, and designing new theoretical methods to model these processes.

During my PhD at the Laboratoire de Chimie Physique Matière Rayonnement, I worked on several aspects of the ultra-fast dynamics of diatomic molecules submitted to strong laser fields. I studied the effect of the permanent dipole moment and polarisability on the tunnel ionization of molecule. I also worked on HHS in diatomic molecules, with a emphase on the harmonic phase and how it allows to get information on the two-center interference that is observed in the HHG spectrum of such molecules. I developed an analytical expansion of the strong field approximation (SFA) formalism that reproduces the results of the numerical solution of the time dependent Schrödinger equation (TDSE). 2DH2_blueyellow_test.jpgWave function of a 2D model of H2

 

XRH2_blueyellow2_test.jpgWave function as a function of electron postion x
and internuclear distance R

I also investigated the ultra-fast nuclear dynamics triggered in homonuclear diatomic molecules by strong infrared (IR) femtosecond pulses. I worked on the interpretation of the phase of the observed oscillations of the nuclear wave packet, based on the Lochfrass (LF) and Bond-Softening (BS) mechanims and I investigated the dynamical correlations between the electron and the nuclei that affect the nuclear dynamics.

 

In collaboration with Felipe Zapata Abellán, Emmanuele Coccia, Julien Toulouse, and Eleonora Luppi at the Laboratoire de Chimie Théorique at Sorbonne Université, and Valérie Véniard at the Laboratoire des Solides Irradiés at École Polytechnique, we developped and thoroughly tested a wave function gaussian based method to model the dynamics of polyelectronic systems submitted to strong laser fields.

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Bielectronic eigenstate of a 1D model of H2+

 

tmp.pngSpatial redirection of an XUV pulse by a He gas
irradiated by a delayed and spatially offset IR pulse

I currently have a postdoc position at Lousiana State University, where I study the collective response of a macroscopic gas sumbitted to short laser pulses by solving the Maxwell's equations coupled to the TDSE. I particularly focus on the ATAS of atoms, and how it can be used to reshape the incoming extreme ultraviolet beam.