A5001864970- Atomic and Molecular Physics
- Laser-Matter Interactions and Applications
- Advanced Chemical Physics Studies
- Mass Spectrometry Techniques and Applications
- Nuclear physics research studies
- Cold Atom Physics and Bose-Einstein Condensates
- Laser-Plasma Interactions and Diagnostics
- Ion-surface interactions and analysis
- Spectroscopy and Quantum Chemical Studies
- Quantum, superfluid, helium dynamics
- Electron and X-Ray Spectroscopy Techniques
- X-ray Spectroscopy and Fluorescence Analysis
- Laser-induced spectroscopy and plasma
- Atomic and Subatomic Physics Research
- Photochemistry and Electron Transfer Studies
- Quantum optics and atomic interactions
- Laser Design and Applications
- Advanced Fiber Laser Technologies
- Advanced X-ray Imaging Techniques
- Advanced Electron Microscopy Techniques and Applications
- Photocathodes and Microchannel Plates
- Molecular spectroscopy and chirality
- Spectroscopy and Laser Applications
- Nuclear Physics and Applications
- Catalysis and Oxidation Reactions
European X-Ray Free-Electron Laser
2021-2025
Max Planck Institute for Nuclear Physics
2023-2025
Kansas State University
2007-2024
University of Science and Technology of China
2024
Goethe University Frankfurt
2013-2022
University of Chicago
2011
Universidad Autónoma de Madrid
2007-2010
Max Planck Society
2010
Crete University Press
2009
University of Crete
2009
Wave-particle duality is an inherent peculiarity of the quantum world. The double-slit experiment has been frequently used for understanding different aspects this fundamental concept. occurrence interference rests on lack which-way information and absence decoherence mechanisms, which could scramble wave fronts. In letter, we report observation two-center in molecular frame photoelectron momentum distribution upon ionization neon dimer by a strong laser field. Postselection ions, were...
Bijvoet's method, which makes use of anomalous x-ray diffraction or dispersion, is the standard means directly determining absolute (stereochemical) configuration molecules, but it requires crystalline samples and often proves challenging in structures exclusively comprising light atoms. Herein, we demonstrate a mass spectrometry approach that images individual molecules gas phase by cold target recoil ion momentum spectroscopy after laser ionization-induced Coulomb explosion. This technique...
Quantum theory dictates that upon weakening the two-body interaction in a three-body system, an infinite number of bound states huge spatial extent emerge just before these become unbound. Three helium atoms have been predicted to form molecular system manifests this peculiarity under natural conditions without artificial tuning attraction between particles by external field. Here we report experimental observation long but experimentally elusive Efimov state $^{4}$He$_{3}$ means Coulomb...
Abstract Following structural dynamics in real time is a fundamental goal towards better understanding of chemical reactions. Recording snapshots individual molecules with ultrashort exposure times key ingredient this goal, as atoms move on femtosecond (10 −15 s) timescales. For condensed-phase samples, ultrafast, atomically resolved structure determination has been demonstrated using X-ray and electron diffraction. Pioneering experiments have also started addressing gaseous samples....
Free-electron lasers (FELs) are the world's most brilliant light sources with rapidly evolving technological capabilities in terms of ultrabright and ultrashort pulses over a large range photon energies. Their revolutionary innovative developments have opened new fields science regarding nonlinear light-matter interaction, investigation ultrafast processes from specific observer sites, approaches to imaging matter atomic resolution. A core aspect FEL is study isolated prototypical systems...
Recently Cederbaum et al. [Phys. Rev. Lett. 79, 4778 (1997)] predicted a new decay channel of excited atoms and molecules termed interatomic Coulombic (ICD). In ICD the deexcitation energy is transferred via virtual photon exchange to neighboring atom, which releases it by electron emission. We report on an experimental observation in $2s$ ionized neon dimers. The process unambiguously identified detecting two ${\mathrm{N}\mathrm{e}}^{1+}$ fragments coincidence, yielding clean, background...
The wave nature of particles is rarely observed, in part because their very short de Broglie wavelengths most situations. However, even with close to the size surroundings, couple environment (for example, by gravity, Coulomb interaction, or thermal radiation). These couplings shift phases, often an uncontrolled way, and resulting decoherence, loss phase integrity, thought be a main cause transition from quantum classical behavior. How much interaction needed induce this transition? Here we...
H 2 , the smallest and most abundant molecule in universe, has a perfectly symmetric ground state. What does it take to break this symmetry? We found that inversion symmetry can be broken by absorption of linearly polarized photon, which itself symmetry. In particular, emission photoelectron with subsequent dissociation remaining + fragment shows no respect ionic neutral atomic fragments. This lack results from entanglement between antisymmetric states is caused autoionization. The...
Although valence electrons are clearly delocalized in molecular bonding frameworks, chemists and physicists have long debated the question of whether core vacancy created a homonuclear diatomic molecule by absorption single x-ray photon is localized on one atom or over both. We been able to clarify this with an experiment that uses Auger electron angular emission patterns from nitrogen after inner-shell ionization as ultrafast probe hole localization. The experiment, along accompanying...
In pioneering work by Cederbaum et al an excitation mechanism was proposed that occurs only in loosely bound matter (Cederbaum 1997 Phys. Rev. Lett. 79 4778): it turned out, (in particular) cases where a local Auger decay is energetically forbidden, excited atom or molecule able to scheme which termed ‘interatomic Coulombic decay’ (or ‘intermolecular decay’) (ICD). As ICD occurs, the energy released transferring atomic molecular neighbor of initially particle. consequence neighboring ionized...
We coincidently measure the molecular frame photoelectron angular distribution and ion sum-momentum of single double ionization CO molecules by using circularly elliptically polarized femtosecond laser pulses, respectively. The orientation dependent rates for various kinetic energy releases allow us to individually identify ionizations multiple orbitals, ranging from highest occupied next two lower-lying orbitals channels observed in our experiments. Not only emission a electron, but also...
Few-photon multiple ionization of Ne and Ar atoms by strong vacuum ultraviolet laser pulses from the free-electron at Hamburg was investigated differentially with Heidelberg reaction microscope. The light-intensity dependence ${\mathrm{Ne}}^{2+}$ production reveals dominance nonsequential two-photon double intensities $I<6\ifmmode\times\else\texttimes\fi{}{10}^{12}\text{ }\text{ }\mathrm{W}/{\mathrm{cm}}^{2}$ significant contributions three-photon as $I$ increases. recoil-ion-momentum...
Fragmentation of highly charged molecular ions or clusters consisting more than two atoms can proceed in a one step synchronous manner where all bonds break simultaneously sequentially by emitting ion after the other. We separated these decay channels for fragmentation ${\mathrm{CO}}_{2}^{3+}$ measuring momenta ionic fragments. show that total energy deposited is control parameter which switches between three distinct pathways: sequential emission an ${\mathrm{O}}^{+}$ leaves rotating...
We report on nonsequential double ionization of Ar by a laser pulse consisting two counterrotating circularly polarized fields (390 and 780 nm). The double-ionization probability depends strongly the relative intensity shows kneelike structure as function intensity. conclude that is driven beam nearly monoenergetic recolliding electrons, which can be controlled in energy field parameters. electron momentum distributions show well second escapes from an intermediate excited state Ar^{+}.
We investigate electron momentum distributions from single ionization of Ar by two orthogonally polarized laser pulses different color. The two-color scheme is used to experimentally control the interference between wave packets released at times within one cycle. This intracycle pattern typically hard resolve in an experiment. With scheme, these features become dominant contribution distribution. Furthermore, second color can be for streaking otherwise interfering establishing a which-way...
Similar to the optical diffraction of light passing through a material grating, Kapitza-Dirac effect occurs when an electron is diffracted by standing wave. In its original description time-independent. present work, we extend concept time domain. By tracking spatiotemporal evolution pulsed wave packet femtosecond (10 15 second) pulse in pump-probe scheme, observe so far unseen time-dependent patterns. The fringe spacing observed pattern differs from that generated conventional effect,...
Coulomb explosion imaging (CEI) with x-ray free electron lasers has recently been shown to be a powerful method for obtaining detailed structural information of gas-phase planar ring molecules [R. Boll et al. Nat. Phys. 18, 423-428 (2022)]. In this Letter, we investigate the potential CEI driven by tabletop laser and extend approach differentiating three-dimensional (3D) structures. We study static patterns nonplanar organic that resemble structures typical products formed in ring-opening...
A high-pressure dc glow discharge based on micro-structured-electrode (MSE) arrays was investigated by diode laser atomic absorption spectroscopy. The microdischarge studied at constant current in pure Ar for pressures ranging from 50 to 400 mbar. measurements of the absolute population density excited 1s5, 1s4, 1s3, and 1s2 levels revealed a atoms metastable resonance states range 1012–1015 cm−3. gas temperature electron number were evaluated analysis line profiles, taking into account...
Using $\mathrm{H}_{2}{}^{+}$ and $\mathrm{D}_{2}{}^{+}$, we observe two-surface population dynamics by measuring the kinetic energy of correlated ions that are created when ($\mathrm{D}_{2}{}^{+}$) ionize in short (40--140 fs) intense (${10}^{14}\text{ }\text{ }\mathrm{W}/{\mathrm{cm}}^{2}$) infrared laser pulses. Experimentally, find a modulation spectrum fragments. The spectral progression arises from hitherto unexpected spatial on excited state population, revealed Coulomb explosion. By...