482 citations · 1.9k across the 46 of their papers we have counts for
21 papers · 1 filter
Attosecond Coherent Electron Motion in a Photoionized Aromatic Molecule
Taran Driver, Zhaoheng Guo, Erik Isele +50
In molecular systems, the ultrafast motion of electrons initiates the process of chemical change. Tracking this electronic motion across molecules requires coupling attosecond time…
Attosecond X-ray Core-level Chronoscopy of Aromatic Molecules
Jia-Bao Ji, Zhaoheng Guo, Taran Driver +32
Attosecond photoemission or photoionization delays are a unique probe of the structure and the electronic dynamics of matter. However, spectral congestion and spatial delocalizatio…
Investigating dissociation pathways of nitrobenzene via mega-electron-volt ultrafast electron diffraction
Kareem Hegazy, James Cryan, Renkai Li +8
As the simplest nitroaromatic compound, nitrobenzene is an interesting model system to explore the rich photochemistry of nitroaromatic compounds. Previous measurements of nitroben…
Femtosecond electronic and hydrogen structural dynamics in ammonia imaged with ultrafast electron diffraction
Elio G. Champenois, Nanna H. List, Matthew Ware +18
Directly imaging structural dynamics involving hydrogen atoms by ultrafast diffraction methods is complicated by their low scattering cross-sections. Here we demonstrate that megae…
Rehybridization dynamics into the pericyclic minimum of an electrcyclic reaction imaged in real-time
Yusong Liu, David M. Sanchez, Matthew R. Ware +17
Electrocyclic reactions are characterized by the concerted formation and cleavage of both σ and π bonds through a cyclic structure. This structure is known as a pericyclic transiti…
Attosecond Coherent Electron Motion in Auger-Meitner Decay
Siqi Li, Taran Driver, Philipp Rosenberger +38
In quantum systems, coherent superpositions of electronic states evolve on ultrafast timescales (few femtosecond to attosecond, 1 as = 0.001 fs = 10^{-18} s), leading to a time dep…
Correlation Driven Transient Hole Dynamics Resolved in Space and Time in the Isopropanol Molecule
T. Barillot, O. Alexander, B. Cooper +46
The possibility of suddenly ionized molecules undergoing extremely fast electron hole dynamics prior to significant structural change was first recognized more than 20 years ago an…
Transient Resonant Auger-Meitner Spectra of Photoexcited Thymine
Thomas J. A. Wolf, Alexander C. Paul, Sarai D. Folkestad +15
We present the first investigation of excited state dynamics by resonant Auger-Meitner spectroscopy (also known as resonant Auger spectroscopy) using the nucleobase thymine as an e…
Strictly Non-Adiabatic Quantum Control of the Acetylene Dication Using an Infrared Field
Chelsea Liekhus-Schmaltz, Xiaolei Zhu, Gregory A. McCracken +3
We demonstrate the existence of a strictly non-adiabatic control pathway in deprotonation of the acetylene dication. This pathway is identified experimentally by measuring a kineti…
Characterizing multiphoton excitation using time-resolved X-ray scattering
Philip H. Bucksbaum, Matthew R. Ware, Adi Natan +2
Molecular iodine was photoexcited by a strong 800 nm laser, driving several channels of multiphoton excitation. The motion following photoexcitation was probed using time-resolved…
Attosecond Transient Absorption Spooktroscopy: a ghost imaging approach to ultrafast absorption spectroscopy
Taran Driver, Siqi Li, Elio G. Champenois +38
The recent demonstration of isolated attosecond pulses from an X-ray free-electron laser (XFEL) opens the possibility for probing ultrafast electron dynamics at X-ray wavelengths.…
Imaging the Photochemical Ring-Opening of 1,3-Cyclohexadiene by Ultrafast Electron Diffraction
T. J. A. Wolf, D. M. Sanchez, J. Yang +20
The ultrafast photoinduced ring-opening of 1,3-cyclohexadiene constitutes a textbook example of electrocyclic reactions in organic chemistry and a model for photobiological reactio…
Ultrafast Photodissociation Dynamics and Nonadiabatic Coupling Between Excited Electronic States of Methanol Probed by Time-Resolved Photoelectron Spectroscopy
Elio G. Champenois, Loren Greenman, Niranjan Shivaram +6
The electronic and nuclear dynamics in methanol, following 156~nm photoexcitation, are investigated by combining a detailed analysis of time-resolved photoelectron spectroscopy exp…
Filming non-radiative population transfer: Time-resolved x-ray scattering near an avoided crossing
Matthew R. Ware, James M. Glownia, James P. Cryan +3
We show that time-resolved x-ray scattering from molecules prepared in a superposition of electronic states moving through an avoided crossing has new features not found in diffrac…
Probing ultrafast ππ*/nπ* internal conversion in organic chromophores via K-edge resonant absorption
T. J. A. Wolf, R. H. Myhre, J. P. Cryan +21
Organic chromophores with heteroatoms possess an important excited state relaxation channel from an optically allowed ππ* to a dark nπ*state. We exploit the element and site specif…
Focal overlap gating in velocity map imaging to achieve high signal-to-noise ratio in photo-ion pump-probe experiments
Niranjan Shivaram, Elio G Champenois, James P Cryan +3
We demonstrate a new technique in velocity map imaging (VMI) that allows spatial gating of the laser focal overlap region in time resolved pump-probe experiments. This significantl…
Ultrafast Isomerization in Acetylene Dication: To Be or Not To Be
Zheng Li, Ludger Inhester, Chelsea Liekhus-Schmaltz +9
Experimental evidence has pointed toward the existence of ultrafast proton migration and isomerization as a key process for acetylene and its ions, however the actual mechanism for…
Rate equations for nitrogen molecules in ultrashort and intense x-ray pulses
Ji-Cai Liu, Nora Berrah, Lorenz S. Cederbaum +4
We study theoretically the quantum dynamics of nitrogen molecules (N) exposed to intense and ultrafast x-rays at a wavelength of 1.1 nm (1100 eV photon energy) from the Linac C…
Delayed Ultrafast X-ray Auger Probing (DUXAP) of Nucleobase Ultraviolet Photoprotection
B. K. McFarland, J. P. Farrell, S. Miyabe +28
We present a new method for ultrafast spectroscopy of molecular photoexcited dynamics. The technique uses a pair of femtosecond pulses: a photoexcitation pulse initiating excited s…
Enhancement of strong-field multiple ionization in the vicinity of the conical intersection in 1,3-cyclohexadiene ring opening
Vladimir S. Petrovic, Sebastian Schorb, Jaehee Kim +9
Nonradiative energy dissipation in electronically excited polyatomic molecules proceeds through conical intersections, loci of degeneracy between electronic states. We observe a ma…
Ultrafast absorption of intense x rays by nitrogen molecules
Christian Buth, Ji-Cai Liu, Mau Hsiung Chen +6
We devise a theoretical description for the response of nitrogen molecules (N2) to ultrashort and intense x rays from the free electron laser (FEL) Linac Coherent Light Source (LCL…