International workshop on theory for attosecond quantum dynamics (IWTAQD) 17



Jun 19 - Jul 11,  2017







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

Oleg I. Tolstikhin MIPT
 Adiabatic Theory, Tunneling ionization
 Jun 19 - Jul 7, 2017
Chiennan Liu Fu-jen catholic U He dynamics under FEL Jun 28 - Jul 11, 2017
Akiyoshi Hishikawa Nagoya U FEL, Molecular dynamics
 Jun 28-29, 2017
Cheng Huang
 Sauthwest U, China
 Molecular Dissociation
Trinh Hoai Vinh RIKEN Attosecond dynamics, Tunneling ionization
 Jun 29, 2017
Hirokazu Hasegawa
 U oof Tokyo
 Molacular orientation
 Jun 29, 2017




Kohji Abe
 UEC Raman, high-rep exp
 Jun 19 - Jul 11,  2017
Masayuki Katsuragawa
 UEC Raman, high-rep exp
 Jun 19 - Jul 11,  2017








Michio Matsuzawa
 UEC
Jun 29, 2017
Shinichi Watanabe
 UEC Many body physics Jun 19 - Jul 11,  2017
Toru Morishita UEC
 Chair
 Jun 19 - Jul 10,  2017
Shun Ohgoda    
UEC
TDSE/Static Field Induced States   
Jun 19 - Jul 11,  2017
Hirokazu Matsui UEC Siegert states Jun 19 - Jul 11,  2017
Jargalsaikhan Amgalan
 UEC Intense laser physics
 Jun 19 - Jul 11,  2017
Hisashi Ishinoda
 UEC Intense laser physics Jun 19 - Jul 11,  2017
Yushiro Suzuki
 UEC Intense laser physics Jun 19 - Jul 11,  2017
Keisuke Kuwabara
 UEC Many body physics
 Jun 19 - Jul 11,  2017
Takahiro Hosaka
 UEC Many body physics Jun 19 - Jul 11,  2017
Chihiro Tokuda
 UEC Many body physics Jun 19 - Jul 11,  2017







Seminar Program(tentative)
June 29  (Thr) 2017@
Place: Bldg. East 6, Rm. 803

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9:30-10:00 FREE DISCUSSION
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10:00-10:40  L.B. Madsen, F. Jensen, A.I. Dnestryan, and Oleg I. Tolstikhin (MIPT)
"Structure factors for tunneling ionization rates of molecules: General Hartree-Fock based integral representation"
Abstract:
In the leading-order approximation of the weak-field asymptotic theory (WFAT), the dependence of the tunneling ionization rate of a molecule in an electric field on its orientation with respect to the field is determined by the structure factor of the ionizing molecular orbital. The WFAT yields an expression for the structure factor in terms of a local property of the orbital in the asymptotic region. However, general quantum chemistry approaches in which molecular orbitals are expanded in Gaussian basis do not reproduce their asymptotic behavior correctly. This hinders the application of the WFAT to polyatomic molecules which are attracting increasing interest in strong-field physics. Recently, an integral-equation approach to the WFAT for tunneling ionization of one electron from an arbitrary potential has been developed. The structure factor is expressed in an integral form as a matrix element involving the ionizing orbital. The integral is not sensitive to the asymptotic behavior of the orbital, which resolves the difficulty mentioned above. Here, we extend the integral representation for the structure factor to many-electron systems treated within the Hartree-Fock method and show how it can be implemented on the basis of standard quantum chemistry software packages. We validate the methodology by considering nobel gas atoms and the CO molecule, for which accurate structure factors exist in the literature. We also present benchmark results for CO2 and for NH3 in the pyramidal and planar geometry.

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10:40-10:50  FREE DISCUSSION
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10:50-11:30 Trinh Hoai Vinh (RIKEN)
"Weak-field asymptotic theory of tunneling ionization: application with Hartree-Fock wave functions"
Abstract:
The weak-field asymptotic theory (WFAT) of tunneling ionization has attracted increasing attention in strong-field community. Including the first-order terms significantly improve its accuracy as verified for one and two-electron systems. For many-electron systems, its application is limited since the exact wave functions are not feasible. In this report, we present initial steps to establish a framework for applying the WFAT to systems whose wave functions are available at Hartree-Fock level.

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11:30-14:00  LUNCH DISCUSSION
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14:00-14:40 Hirokazu Hasegawa (U of Tokyo)
"Field-free molecular orientation of OCS"
Abstract:
The Field-free molecular orientation of OCS induced by a two-color intense femtosecond laser pulse (orientation pulse) has been studied. We demonstrate that the orientation degree is enhanced by using an ensemble of aligned OCS molecules, which is created by irradiating with an intense femtosecond laser pulse (alignment pulse) prior to the orientation pulse.

14:40-15:20 Akiyoshi Hishikawa (Nagoya U)
"Photoelectron interference from Rydberg states of He in strong laser fields"
Abstract:
Strong laser field ionization of He 2^1P (800nm, ~10^13 W/cm^2) was studied by photoelectron spectroscopy. Observed photoelectron spectra show two strong peaks due to the Freeman resonance to the 5f and 6f Rydberg states, which undergo ultrashort two-photon Rabi flopping. In addition to these prominent peaks, a series of weak interference patterns were identified. Possible scenarios producing the photoelectron interference will be discussed.

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15:20-15:40  FREE DISCUSSION
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 15:40-16:10
Trivikramarao Gavara (UEC)
"Development of injection locked laser and its application to continuous wave based optical waveform generati"
Abstract:
We present the injection locked continuous wave laser which can operate at multiple frequencies as well as single frequency. The fundamental laser features such as frequency purity and transverse mode profiles are discussed briefly.  As the advanced features desirable two frequency separation and controllable relative output power ratios are showed. As an application of the injection locked Ti:sapphire laser, generation of 1.6 fs optical pulses with a repetition rate of 125 THz, based on the five phase-locked harmonics using the amplitude and phase manipulation techniques[1,2] are presented.
References:
1)    K.Yoshii, J. K. Anthony, and M. Katsuragawa,hThe simplest route to generating a train of attosecond pulsesh, Light: Science & applications 2, 58(2013).
2)    M.Katsuragawa and K. Yoshii,hArbitrary manipulation of amplitude and phase of a set of highly discrete coherent spectrah,PRA 95, 033846 (2017).

16:10-16:40 Chiennan Liu (Fu-jen catholic U)
"A preliminary study on tunneling of doubly excited states of helium"
Abstract:
In the hypersherical picture, tunneling of one of the electrons in a doubly excited state of helium could occur through one of the hyperspherical adiabatic potential, analogous to tunneling ionization of atoms in the presence of an external static electric field. However, there is an additional complication due to the competing decay mechanism of autoionization. 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. Photoelectron spectra and momentum distributions will be presented with signals of tunneling of doubly excited states identified. The weak-field asymptotic theory is applied to gain insights into these results.

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16:40-19:10 FREE DISCUSSION
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Toru Morishita,UEC