International workshop on theory for attosecond quantum dynamics (IWTAQD) 22

Jan 13 -Feb 1, 2020

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Participants (Bldg. E-6, Rms. 525, 527)

Oleg I. Tolstikhin MIPT
Adiabatic Theory, Tunneling ionization
Jan 13 - Feb 1, 2020
Chiennan Liu Fu-jen catholic U He dynamics under FEL/IR laser fields
Jan 13-20, 2020
Akiyoshi Hishikawa Nagoya U FEL, Molecular dynamics
Jan 20-22, 2020
Ryuji Itakura
Multi orbital effect on molecular tunneling ionization
Jan 20-22, 2020
Susumu Kuma
FEL experiment
Jan 21, 2020

Jens Svensmark UEC Molecular dynamics in intense laser fields Jan 13 - Feb 1, 2020
Shinichi Watanabe
UEC Many body physics Jan 13 - Feb 1, 2020

Toru Morishita UEC
Jan 13 - Feb 1, 2020

Hirokazu Matsui UEC Molecular ionization
Jan 13 - Feb 1, 2020
Yushiro Suzuki UEC Trilobite structure
Jan 13 - Feb 1, 2020

Shota Ito
UEC Strong Field Physics Jan 13 - Feb 1, 2020
Kakeru Furuhata
Strong Field Physics Jan 13 - Feb 1, 2020
Yoshiaki Watanabe
Strong Field Physics
Jan 13 - Feb 1, 2020
Motohide Aoki
UEC Molecular Dynamics
Jan 13 - Feb 1, 2020
Tsukasa Asami
UEC Molecular Dynamics Jan 13 - Feb 1, 2020
Chiaki Oshiro
UEC Molecular Dynamics Jan 13 - Feb 1, 2020

Plenary session/seminar Program


Jan 21  (Tue) 2020
Place: E6-803

10:00-10:45   Oleg I. Tolstikhin (MIPT) and Toru Morishita
Strong-field ionization, rescattering, and target structure imaging with vortex electrons"
Manifestations of and possibilities related to vortex electrons in strong-field physics are discussed. We present a theory which extends the foundation of a powerful method of target structure and dynamics imaging to vortex electrons. The theory enables one to extract the differential cross section (DCS) for elastic scattering of a vortex electron on the parent ion\a collision property introduced here\from the observable photoelectron momentum distribution (PEMD). We illustrate this by considering strong-field ionization from orbitals in two atoms, Xe and He+, and a molecule, O_2. The vortex DCS is shown to be sensitive to the target structure. The PEMDs formed by vortex electrons are predicted to be sensitive to the chirality of the target. Extracting vortex DCSs from experimental PEMDs may open a new avenue for rescattering photoelectron spectroscopy.

10:45-11:30 Akiyoshi Hishikawa (Nagoya U)
"Dissociative tunneling-ionization of H2 and D2 in circularly polarized intense laser fields"
Tunneling ionization of molecular hydrogen in intense laser fields (10^14 W/cm^2) has been studied by electron-ion coincidence momentum imaging. The momentum distribution of the electron produced by dissociative ionization, H2 -> H+H^++e^-, is recorded in the molecular frame.  Characteristic properties of the angular distributions are discussed, in particular, by comparison with predictions by WFAT. 


14:00-14:45 Ryuji Itakura (QST)
"Photoelectron emission from multiple orbitals of ethanol and methanol in intense laser fields"
Abstract:  doc file
We investigate the photoelectron emission dynamics of ethanol and methanol in intense laser fields by photoelectron-photoion coincidence 3D imaging.  Two experimental results will be presented.  The first one is the orbital deformation of ethanol prior to electron emission in a circularly polarized near-infrared laser field.  Discussion is made on the basis of the orientation dependent tunneling ionization probability [1].  The second result is the orientation-resolved molecular-frame photoelectron angular distribution of methanol in a linearly polarized ultraviolet laser field.  The photoelectron from HOMO-2 is anomalously emitted in the direction perpendicular to the laser polarization when the molecule is oriented perpendicularly to the laser polarization.

[1] H. Akagi, T. Otobe, R. Itakura, Sci. Adv. 5, eaaw1885 (2019).

14:45-15:30 Hirokazu Matsui (UEC)
"Benchmark weak-field asymptotic theory results for tunneling ionization of hydrogen molecule"
Abstract: doc file
We analytically study the tunneling ionization rate of hydrogen molecule in ground state by applicating Many-Electron Weak-Field Asymptotic Theory (ME-WFAT) with Born-Oppenheimer Approximation (BOA). We numerically calculate the alignment angle dependence and the isotope (H_2 and D_2) effect of ionization rate with some corrections which implies the molecule originated effects: dipole coupling of H_2^+ and D_2^+ (core polarization), localization of the bound electron on one of nucleus (spectator nucleus) and inter-nuclear motion. Our theoretical results are compared with fully correlated calculations and experimental results in order to investigate the contribution of the molecule originated effects to the tunneling ionization process of hydrogen molecule. Moreover, the many electron effect is also evaluated by comparing our results with Single-Active-Electron Approximation (SAEA) results.


15:45-16:30 Jens Svensmark(UEC)
"Adiabatic theory of strong-field ionization of molecules including nuclear motion"
The adiabatic theory of tunneling ionization has been successfully used to describe tunneling ionization of atoms [Phys. Rev. A 86, 043417 (2012)]. This theory works particularly well for describing systems in strong, slowly oscillating laser fields in the near and far-infrared parts of the spectrum; a regime of laser parameters that are currently receiving a lot of attention within strong field physics. In this work we seek to apply the adiabatic theory to molecular systems, while treating both nuclear and electronic degrees of freedom. We propose a theory that combines adiabatic theory with a variation of the well known Born-Oppenheimer approximation. The results of this theory is compared to accurate TDSE calculations.

16:30-16:55 Susumu Kuma (Riken)
"Superfluorescence in the extreme ultraviolet range on ionization and excitation by a soft X-ray free-electron laser"
Superfluorescence, a cooperative and coherent emission, was firstly demonstrated in the extreme ultraviolet range.  Soft X-ray ultrashort pulses from the SACLA free-electron laser ionized He atoms in a dense helium gas, and successively populated the He$^{+}$ 4p state. We identified cascade and yoked (simultaneous) superfluorescences experimentally, which were further confirmed by a numerical study using the Maxwell-Liouville equation for simulating the propagation of the ultrashort excitation and superfluorescent pulses.


Toru Morishita,UEC