International workshop on theory for attosecond quantum dynamics (IWTAQD) 18



Jan 15 - Feb 7,  2018, co-hosted by Institute of Advanced Science (IAS), UEC.



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

Oleg I. Tolstikhin MIPT
 Adiabatic Theory, Tunneling ionization
 Jan 15 - Feb 3, 2018
Chiennan Liu Fu-jen catholic U He dynamics under FEL/IR laser
Jan 24 - Feb 7, 2018
Akiyoshi Hishikawa Nagoya U FEL, Molecular dynamics
 Feb 29-30, 2018
Toshiyuki Azuma
 RIKEN
 Ion trap, atomic ionization
 Feb 29
Yueming Zhou Huazhong U. of Science &Tech.
 Strong-Field Photoelectron Holography
 Jan 17 - Feb 5




Kohji Abe
 UEC
 Raman, high-rep exp Jan 15 - Feb 7,  2018
Masayuki Katsuragawa
 UEC
 Raman, high-rep exp Jan 15 - Feb 7,  2018
Jens Svensmark UEC
 Molacular dynaimcs in intese laser fields
 Jan 15 - Feb 7,  2018
Tor Kjellsson Lindblom UEC
 Relativistic effects in strong field phyics
 Jan 15 - Feb 7,  2018
Michio Matsuzawa
 UEC
 Rydberg atom
 Jan 29, 2018
Shinichi Watanabe
 UEC Many body physics Jan 15 - Feb 7,  2018
Toru Morishita UEC
 Chair
 Jan 15 - Feb 7,  2018
Shun Ohgoda    
UEC
TDSE/Static Field Induced States   
Jan 15 - Feb 7,  2018
Hirokazu Matsui UEC Siegert states, Adiabatic transition
 Jan 15 - Feb 7,  2018
Jargalsaikhan Amgalan
 UEC Intense laser physics
 Jan 15 - Feb 7,  2018
Hisashi Ishinoda
 UEC Intense laser physics Jan 15 - Feb 7,  2018
Yushiro Suzuki
 UEC Intense laser physics Jan 15 - Feb 7,  2018
Keisuke Kuwabara
 UEC Many body physics
 Jan 15 - Feb 7,  2018
Takahiro Hosaka
 UEC Many body physics Jan 15 - Feb 7,  2018
Chihiro Tokuda
 UEC Many body physics Jan 15 - Feb 7,  2018







Seminar Program(tentative)
Jan 29  (Mon) 2018
Place: Bldg. East 6, Rm. 803

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10:00-11:00 FREE DISCUSSION
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11:00-11:40   Toru Morishita and Oleg I. Tolstikhin (MIPT)
"Adiabatic theory of strong-field photoelectron momentum distributions near a backward rescattering caustic"
Abstract:
We present a comprehensive treatise on the derivation of the factorization formula describing strong-field photoelectron momentum distributions near the outermost backward rescattering caustic within the adiabatic theory and its validation by calculations. The formuladerived holds for ionization by linearly polarized laser pulses of sufficiently low frequency and becomes exact as the frequency tends to zero for a fixed pulse amplitude. The convergence of the results obtained from the formula to accurate photoelectron momentum distributions obtained by solving the time-dependent Schroedinger equation is demonstrated. The formula is shown to work quantitatively in both tunneling and over-the-barrier regimes of ionization for finite-range potentials as well as potentials with a Coulomb tail. This paves the way for future applications of the present theory in strong-field physics. In particular, the explicit analytical form of the returning photoelectron wave packet given here enables one to extract differential cross sections for elastic scattering of a photoelectron on the parent ion from experimental photoelectron momentum distributions.

11:40-12:20 　Jens Svensmark (UEC)
"Tunneling ionization of diatomic molecules"
Abstract:
The Born-Oppenheimer approximation, which is very often used in calculations on molecules, breaks down for weak fields when describing tunneling ionization. This perhaps surprising result means that most traditional ways of solving the tunneling ionization problem based on the Born-Oppenheimer approximation give wrong results for weak fields. As an alternative to the Born-Oppenheimer approximation the weak-field asymptotic theory can be used to accurately calculate ionization rates in the weak-field limit.

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12:20-14:00  LUNCH DISCUSSION
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14:00-14:30 Akiyoshi Hishikawa (Nagoya U)
"Three-dimensional photoelectron momentum imaging of deuterated molecular hydrogen in circularly polarized intense laser fields"
Abstract:
Three-dimensional photoelectron momentum distributions of D2 in circularly polarized intense laser fields (800 nm, 1014 W/cm2) have been recorded by a newly constructed coincidence momentum imaging setup. Their properties and the field intensity dependence will be reported.

14:40-15:10 Yueming Zhou (Huazhong University of Science and Technology, Wuhan 430074, China)
"Monitoring Attosecond valence electron dynamics with strong-field photoelectron holography"
Abstract:
Coherent superposition of several valence electronic states in molecules induces ultrasfast motion of the electron wavepacket. Monitoring this electron motion requires measurements with subatomic spatial and attosecond temporal resolutions. We will show that strong-field photoelectron holography (SFPH), which originates from the interference of electrons flying directly to the detector after tunneling ionization and those undergoing near-forward rescattering by the parent ion, could access this realm. We show that the transient location of the moving electron wavepacket is uniquely mapped to the phase of transverse momentum amplitude in strong-field tunneling ionization. This phase is manifested in the holographic fringes of the photoelectron momentum distribution. By extracting this phase from the hologram, the attosecond electron motion in molecules could be directly visualized without reconstruction procedure and information of the involved states. The validity and accuracy of this scheme is confirmed by applying it to the prototypical molecule H2+.

15:10-15:50 Tor Kjellsson Lindblom (Stockholm U, UEC)
"Relativistic light-matter interaction beyond the dipole approximation"
Abstract:
With the steady development of increasing peak intensity of laser pulses, laser-matter experiments where relativistic and high-order multipole effects are important may soon become available. To estimate the theoretical threshold for these type of effects, we have solved the time dependent Schrödinger and Dirac equations beyond the electric dipole approximation. In addition to some preliminary indications, I will also present a new framework for the interaction (Physical Review A96 023426) which shows superior numerical convergence properties in comparison with the so called velocity gauge (minimal coupling).

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15:50-16:10 FREE DISCUSSION
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16:10-16:50 Toshiyuki Azuma (RIKEN)
"Dynamics and spectroscopy of cold molecular ions stored in RIKEN cryogenic electrostatic ring (RICE)"
Abstract:
A new electrostatic ion storage ring, the RIKEN cryogenic electrostatic ring, has been successfully commissioned recently with a 15-keV ion beam under cryogenic conditions. This ring has a capability to keep isolated ions for more than a few minutes in ultra-high vacuum under the circumstance of 4.2 K. Presently we are under measurement of rotational level distribution by action spectroscopy using a wave-tunable visible laser. Present status of several cryogenic storage rings over the world and projects to introduce a tunable IR laser or a short pulse intense laser into the ring will be reported

16:50-17:30 Chiennan Liu (Fu-jen catholic U)
"Progress report on tunneling ionization of doubly excited states of helium"
Abstract:
We investigate the scenario that doubly excited states below the He+(n=2) threshold are first populated by an XUV pulse and subsequently tunnel ionized by an IR pulse by solving the time-dependent Schrödinger equation in the hyperspherical coordinates. In addition to tunneling ionization, autoionization is a competing decay mechanism.

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17:30-19:30 FREE DISCUSSION
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Toru Morishita,UEC