A5059303078- Laser-Matter Interactions and Applications
- Spectroscopy and Quantum Chemical Studies
- Advanced Chemical Physics Studies
- Mass Spectrometry Techniques and Applications
- Molecular Junctions and Nanostructures
- Photochemistry and Electron Transfer Studies
- Advanced Fiber Laser Technologies
- Atomic and Molecular Physics
- Quantum optics and atomic interactions
- Astrophysics and Star Formation Studies
- Quantum Information and Cryptography
- Strong Light-Matter Interactions
- Molecular Spectroscopy and Structure
- Quantum Electrodynamics and Casimir Effect
- Cold Atom Physics and Bose-Einstein Condensates
- Electron Spin Resonance Studies
- Photosynthetic Processes and Mechanisms
- Fullerene Chemistry and Applications
- Ion-surface interactions and analysis
Institut Lumière Matière
2013-2024
Université Claude Bernard Lyon 1
2015-2024
Centre National de la Recherche Scientifique
2015-2024
Heidelberg University
2017-2023
Heidelberg Institute for Theoretical Studies
2020
Hole migration is a fascinating process driven by electron correlation, in which purely electronic dynamics occur on very short time scale complex ionized molecules, prior to the onset of nuclear motion. However, it expected that due coupling dynamics, these oscillations will be rapidly damped and smeared out, makes experimental observation hole rather difficult. In this Letter, we demonstrate instantaneous ionization benzene molecules initiates an ultrafast characterized periodic breathing...
Photoinduced molecular processes start with the interaction of instantaneous electric field incident light electronic degrees freedom. This early attosecond motion impacts fate photoinduced reactions. We report first observation time scale electron dynamics in a series small- and medium-sized neutral molecules (N(2), CO(2), C(2)H(4)), monitoring time-dependent variations parent ion yield ionization by an pulse, thereby probing dipole induced moderately strong near-infrared laser field....
Abstract Highly excited molecular species are at play in the chemistry of interstellar media and involved creation radiation damage a biological tissue. Recently developed ultrashort extreme ultraviolet light sources offer high excitation energies ultrafast time-resolution required for probing dynamics highly states on femtosecond (fs) (1 fs=10 −15 s) even attosecond (as) as=10 −18 timescales. Here we show that polycyclic aromatic hydrocarbons (PAHs) undergo relaxation few tens femtoseconds...
Ionization of molecules very often populates several cationic states launching pure electron dynamics that appear as ultrafast migration the hole charge throughout system. A crucial question in emerging field attochemistry is whether these electronic coherences last long enough to allow for their efficient observation and eventual manipulation with ultrashort laser pulses. We report a full-dimensional quantum calculation concerted electron-nuclear initiated by outer-valence ionization...
Abstract Observing the crucial first few femtoseconds of photochemical reactions requires tools typically not available in femtochemistry toolkit. Such dynamics are now within reach with instruments provided by attosecond science. Here, we apply experimental and theoretical methods to assess ultrafast nonadiabatic vibronic processes a prototypical complex system—the excited benzene cation. We use few-femtosecond duration extreme ultraviolet visible/near-infrared laser pulses prepare probe...
The many-body quantum nature of molecules determines their static and dynamic properties, but remains the main obstacle in accurate description. Ultrashort extreme ultraviolet pulses offer a means to reveal molecular dynamics at ultrashort timescales. Here, we report use time-resolved electron-momentum imaging combined with attosecond study highly excited organic molecules. We measure relaxation timescales that increase state energy. High-level calculations show these are intrinsic...
Experiments selectively excite and probe specific core electrons in CH${}_{2}$I${}_{2}$ to follow the molecule's internal dynamics also pave way toward site-selective control of chemical reactions.
Using direct search algorithms for solving the quantum optimization problem, we demonstrate on model systems that with specifically tailored Gaussian-form laser pulses one can achieve a very good control over dynamics in complicated systems. We show by manipulating limited number of laser-pulse parameters, is able to charge migration process molecules. In particular, combining two identical Gaussian an appropriate delay between them, stop pure electronic, few-femtosecond oscillation charge,...
Due to the electron correlation, fast removal of an from a molecule may create coherent superposition cationic states and in this way initiate pure electronic dynamics which hole-charge left by ionization migrates throughout system on ultrashort time scale. The coupling nuclear motion introduces decoherence that eventually traps charge, crucial questions field attochemistry include how long coherence lasts degrees freedom are mostly responsible for decoherence. Here, we report...
Unraveling ultrafast dynamical processes in highly excited molecular species has an impact on our understanding of chemical such as combustion or the composition clouds universe. In this article we use short (<7 fs) XUV pulses to produce cationic states benzene molecules and probe their dynamics using few-cycle VIS/NIR laser pulses. The produced by lie especially complex spectral region where multi-electronic effects play a dominant role. We show that very fast τ ≈ 20 fs nonadiabatic...
We present dynamics calculations showing how electron-correlation-driven charge migration occurring in the correlation band of ionized molecules can lead to a redistribution increasing stability system. These offer an interpretation recent experimental results obtained for adenine. discuss implications mechanism development attochemistry and it be understood context ultrafast, non-adiabatic relaxation taking place highly-excited molecular cations.
Photo-ionization induced ultrafast electron dynamics is considered as a precursor for the slower nuclear associated with molecular dissociation. Here, using ab initio multielectron wave-packet propagation method, we study overall many-electron dynamics, triggered by ionizing outer-valence orbitals of different tautomers prototype molecule more than one symmetry element. From time evolution initially created averaged hole density each system, identify distinctly charge responses in tautomers....
We report the experimental observation of quantum interference in nuclear wave-packet dynamics driving ultrafast excitation-energy transfer argon dimers below threshold interatomic Coulombic decay (ICD). Using time-resolved photoion-photoion coincidence spectroscopy and simulations, we reveal that electronic relaxation inner-valence 3s hole on one atom leading to a 4s or 4p excitation other is influenced by initial state, giving rise deep, periodic modulation kinetic-energy-release (KER)...
Ultrafast XUV chemistry is offering new opportunities to decipher the complex dynamics taking place in highly excited molecular states and thus better understand fundamental natural phenomena as molecule formation interstellar media. We used ultrashort light pulses perform pump-IR probe experiments caffeine a model of prebiotic molecule. observed 40 fs decay cationic states. Guided by quantum calculations, this time scale interpreted terms nonadiabatic cascade through large number correlated...
XUV induced dynamics in molecules is still largely unexplored while experimental and theoretical tools are becoming available several labs. In this work, we present a compact beamline designed to induce probe femtosecond attosecond gas samples (from atoms complex molecular species). The processes studied with time-resolved photoelectron or/and photoion imaging. characterization of the performances setup presented. We show results obtained naphthalene molecule showing imaging experiments...
We have studied theoretical photoelectron-momentum distributions of ${\mathrm{C}}_{60}$ using time-dependent density functional theory (TDDFT) in real time and including a self-interaction correction. Our calculations furthermore account for proper orientation averaging allowing direct comparison with experimental results. To illustrate the capabilities this (microscopic time-dependent) approach, two very different photo-excitation conditions are considered: excitation high-frequency XUV...
An investigation of how polycyclic aromatic hydrocarbons respond to extreme ultraviolet radiation provides insight into internal molecular dynamics that can help improve models interstellar chemistry.
The possibility of observing correlation-driven charge migration has been a driving force behind theoretical and experimental developments in the field attosecond molecular science since its inception. Despite significant accomplishments, unambiguous observation this quantum beating remains elusive. In work, we present method to selectively trigger such dynamics using molecules predicted exhibit long-lived electron coherence. We show that these can be triggered infrared multi-photon...
Correlation-driven charge migration initiated by inner-valence ionization leading to the population of correlation bands alkyne chains containing between 4 and 12 carbon atoms is explored through ab initio simulations. Scaling laws are observed, both for time scale slope density states bands. These can be used predicting relaxation in much larger systems from same molecular family finding promising candidates development an attochemistry scheme taking advantages specificity dynamics molecules.
We investigate the attosecond response of electronic cloud a molecular system to an outer-valence ionization. The time needed for remaining electrons respond sudden perturbation in structure molecule is measure degree electron correlation. Using ab initio multielectron wave-packet propagation method, we analyze ultrafast many-body dynamics following removal different two tautomers uracil and show that this can be sensitive symmetry ionized orbital.