Publications (37)
Observation of enhanced chiral asymmetries in the inner-shell photoionization of uniaxially oriented methyloxirane enantiomers
Maurice Tia, Martin Pitzer, Gregor Kastirke +38
Most large molecules are chiral in their structure: they exist as two enantiomers, which are mirror images of each other. Whereas the rovibronic sublevels of two enantiomers are al…
Multiple charge transfer driven complex reaction dynamics: covalent bonding meets van der Waals interactions
Ruichao Dong, Xiaoqing Hu, Owen Dennis McGinnis +22
Ultrafast charge transfer (CT) processes redistribute electronic charge within and between molecular units and play a central role in many physical, chemical, and biological phenom…
Circular RABBITT goes under threshold
Vladislav V. Serov, Jia-Bao Ji, Meng Han +3
We introduce circular under-threshold RABBITT (cuRABBITT) as a new interferometric method to probe discrete electronic excitations in atoms with attosecond resolution. By combining…
Atomic, molecular and optical physics applications of longitudinally coherent and narrow bandwidth Free-Electron Lasers
Carlo Callegari, Alexei N. Grum-Grzhimailo, Kenichi L. Ishikawa +3
Short wavelength Free-Electron Lasers (FELs) are the newest light sources available to scientists to probe a wide range of phenomena, with chemical, physical and biological applica…
Auger decay of molecular double core-hole state
Motomichi Tashiro, Kiyoshi Ueda, Masahiro Ehara
We report on theoretical Auger electron kinetic energy distribution originated from sequential two-step Auger decays of molecular double core-hole (DCH) state, using CH4, NH3 and H…
Three-Dimensional Shapes of Spinning Helium Nanodroplets
Bruno Langbehn, Katharina Sander, Yevheniy Ovcharenko +23
A significant fraction of superfluid helium nanodroplets produced in a free-jet expansion have been observed to gain high angular momentum resulting in large centrifugal deformatio…
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…
Double core-hole electron spectroscopy for open-shell molecules: theoretical perspective
Motomichi Tashiro, Masahiro Ehara, Kiyoshi Ueda
We have theoretically investigated the double core-hole (DCH) states of the open-shell molecules and examined the possibility of DCH spectroscopy by means of X-ray two-photon photo…
Relation Between Photoionisation Cross Sections and Attosecond Time Delays
Jia-Bao Ji, Anatoli S. Kheifets, Meng Han +2
Determination and interpretation of Wigner-like photoionisation delays is one of the most active fields of attosecond science. Previous results have suggested that large photoionis…
A new method for measuring angle-resolved phases in photoemission
Daehyun You, Kiyoshi Ueda, Elena V. Gryzlova +33
Quantum mechanically, photoionization can be fully described by the complex photoionization amplitudes that describe the transition between the ground state and the continuum state…
Experimental Demonstration of Attosecond Pump-Probe Spectroscopy with an X-ray Free-Electron Laser
Zhaoheng Guo, Taran Driver, Sandra Beauvarlet +47
Pump-probe experiments with sub-femtosecond resolution are the key to understanding electronic dynamics in quantum systems. Here we demonstrate the generation and control of sub-fe…
Photoionization time delays probe electron correlations
Mingxuan Li, Huiyong Wang, Rezvan Tahouri +16
The photoelectric effect, explained by Einstein in 1905, is often regarded as a one-electron phenomenon. However, in multi-electron systems, the interaction of the escaping electro…
Zepto to Attosecond core-level photoemission time delays in homonuclear diatomic molecules and non-dipole effects in the framework of Multiple Scattering theory
Yoshiaki Tamura, Kaoru Yamazaki, Kiyoshi Ueda +1
This study theoretically investigates the angular distribution of core-level photoemission time delay within a molecular frame. This phenomenon can be measured with the advancement…
Theory of polarization-averaged core-level molecular-frame photoelectron angular distributions: III. New formula for p- and s-wave interference analogous to Young's double-slit for core-level photoemission from hetero-diatomic molecules
Fukiko Ota, Kaoru Yamazaki, Didier Sébilleau +2
We present a new variation of Young's double-slit formula for polarization-averaged molecular-frame photoelectron angular distributions (PA-MFPADs) of hetero-diatomic molecules, wh…
Separation of Wigner and Continuum-continuum Delays by Mirror-symmetry-broken Attosecond Interferometry
Meng Han, Jia-Bao Ji, Leung Chung Sum +2
Photoionization of matter is one of the fastest electronic processes in nature. Experimental measurements of photoionization dynamics have become possible through attosecond metrol…
Interferometric extraction of photoionization-path amplitudes and phases from time-dependent multiconfiguration self-consistent-field simulations
Yuki Orimo, Oyunbileg Tugs, Takeshi Sato +3
Bichromatic extreme-ultraviolet pulses from a seeded free-electron laser enable us to measure photoelectron angular distribution (PAD) as a function of the relative phase between t…
Deep neural networks for classifying complex features in diffraction images
Julian Zimmermann, Bruno Langbehn, Riccardo Cucini +13
Intense short-wavelength pulses from free-electron lasers and high-harmonic-generation sources enable diffractive imaging of individual nano-sized objects with a single x-ray laser…
Experimental Realization of All-Optical Terahertz Attoclock
Yanjun Gao, Yizhu Zhang, Yulin Chen +8
The attoclock is a powerful tool for probing ultrafast electron dynamics with attosecond precision.Here, we demonstrate an all-optical terahertz (THz) attoclock that reconstructs p…
Redirection and Reshaping of Intense Extreme-Ultraviolet Radiation
Yu He, Alexander Magunia, Harijyoti Mandal +29
The goal to control short-wavelength radiation for the investigation and manipulation of ultrafast dynamics in quantum systems coevolves with the growing availability of extreme-ul…
Two-center Interference in the Photoionization Delays of Kr2
Saijoscha Heck, Meng Han, Denis Jelovina +6
We present the experimental observation of two-center interference in the ionization time delays of Kr2. Using attosecond electron-ion-coincidence spectroscopy, we simultaneously m…
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…
Control of ion-photoelectron entanglement and coherence via Rabi oscillations
Kenichi L. Ishikawa, Kevin C. Prince, Kiyoshi Ueda
We report a theoretical investigation of photoionization by a pair of coherent, ultrashort fundamental and second-harmonic extreme-ultraviolet pulses, where the photon energies are…
Laser-assisted Fano resonance: attosecond quantum control and dynamical imaging
Meng Han, Hao Liang, Jia-bao Ji +4
A Fano resonance arises from the pathway interference between discrete and continuum states, playing a fundamental role in many branches of physics, chemistry and material science.…
XCALIB: a focal spot calibrator for intense X-ray free-electron laser pulses based on the charge state distributions of light atoms
Koudai Toyota, Zoltan Jurek, Sang-Kil Son +7
We develop the XCALIB toolkit to calibrate the beam profile of an X-ray free-electron laser (XFEL) at the focal spot based on the experimental charge state distributions (CSDs) of…
Molecular double core-hole electron spectroscopy for chemical analysis
Motomichi Tashiro, Masahiro Ehara, Hironobu Fukuzawa +4
We explore the potential of double core hole electron spectroscopy for chemical analysis in terms of x-ray two-photon photoelectron spectroscopy (XTPPS). The creation of deep singl…
Observation of Strong Electron Correlation in Planetary Atomic Structure
Xinglong Yu, Yongyan Han, Zhenjie Shen +10
Unravelling two-electron correlation is a long-standing challenge at the heart of few-body quantum physics, underlying correlated phenomena across atomic, molecular and condensed-m…
Analytical Expression for Continuum-continuum Transition Amplitude of Hydrogen-like Atoms with Angular-momentum Dependence
Jia-Bao Ji, Kiyoshi Ueda, Meng Han +1
Attosecond chronoscopy typically utilises interfering two-photon transitions to access the phase information. Simulating these two-photon transitions is challenging due to the cont…
High-Energy Molecular-Frame Photoelectron Angular Distributions: A Molecular Bond-Length Ruler
Isabel Vela-Peréz, Fukiko Ota, Abir Mhamdi +24
We present an experimental and theoretical study of core-level ionization of small hetero- and homo-nuclear molecules employing circularly polarized light and address molecular-fra…
Theory on polarization-averaged core-level molecular-frame photoelectron angular distributions: I. A Full-potential method and its application to dissociating carbon monoxide dication
Fukiko Ota, Kaoru Yamazaki, Didier Sébilleau +2
We present a theoretical study on polarization-averaged molecular-frame photoelectron angular distributions (PA-MFPADs) emitted from orbital of oxygen atom of dissociating dic…
Diffraction imaging of light induced dynamics in xenon-doped helium nanodroplets
Bruno Langbehn, Yevheniy Ovcharenko, Andrew Clark +23
We have explored the light induced dynamics in superfluid helium nanodroplets with wide-angle scattering in a pump-probe measurement scheme. The droplets are doped with xenon atoms…
Theory on polarization-averaged core-level molecular-frame photoelectron angular distributions: II. Extracting the X-ray induced fragmentation dynamics of carbon monoxide dication from forward and backward intensities
Fukiko Ota, Keisuke Hatada, D Sébilleau +2
Recent developments of high-reputation-rate X-ray free electron lasers (XFELs) such as European XFEL and LSCS-II, combined with coincidence measurements at the COLTRIMS-Reaction Mi…
Competition of resonant and nonresonant paths in resonance-enhanced two-photon single ionization of He by an ultrashort extreme-ultraviolet pulse
Kenichi L. Ishikawa, Kiyoshi Ueda
We theoretically study the pulse-width dependence of the photoelectron angular distribution (PAD) from the resonance-enhanced two-photon single ionization of He by femtosecond ($\l…
Attosecond metrology in circular polarization
Meng Han, Jia-bao Ji, Kiyoshi Ueda +1
Attosecond metrology with linearly polarized light pulses is the basis of a highly successful research area. An even broader impact can be expected from a generalized metrology tha…
Disentangling the Evolution of Electrons and Holes in photoexcited ZnO nanoparticles
Christopher J. Milne, Natalia Nagornova, Thomas Pope +27
The evolution of charge carriers in photoexcited room temperature ZnO nanoparticles in solution is investigated using ultrafast ultraviolet photoluminescence spectroscopy, ultrafas…
Zeptosecond Angular Streak Camera
Hongcheng Ni, Stefan Donsa, Xiaochun Gong +3
Time-resolved electronic processes on the attosecond scale have recently become experimentally accessible through the development of laser-based pump-probe interrogation techniques…
Attosecond Pulse-shaping using a seeded free-electron laser
Praveen Kumar Maroju, Cesare Grazioli, Michele Di Fraia +41
Attosecond pulses are fundamental for the investigation of valence and core-electron dynamics on their natural timescale. At present the reproducible generation and characterisatio…
Theoretical study of pulse delay effects in the photoelectron angular distribution of near-threshold EUV+IR two-photon ionization of atoms
Kenichi L. Ishikawa, A. K. Kazansky, N. M. Kabachnik +1
We theoretically study the photoelectron angular distributions (PADs) from two-color two-photon near-threshold ionization of hydrogen and noble gas (He, Ne, and Ar) atoms by a comb…