[12a-PA2-1~6] 3.6 Ultrashort-pulse and high-intensity lasers

▼ [12a-PA2-6] Time-Dependent First-Principle Simulations on the Resonant High-Harmonic Generation from Transition Metal Plasma

〇(D)Imam Setiawan Wahyutama¹, Takeshi Sato^1,2,3, Kenichi Ishikawa^1,2,3 (1.Dept. of Nuclear Eng. and Management, School of Eng. The Univ. of Tokyo, 2.Photon Science Center, School of Eng., The Univ.of Tokyo, 3.Research Inst. for Photon Science and Laser Technology, The Univ. of Tokyo)

Keywords:HHG, resonance, TD-CASSCF

Resonant high-harmonic generation (HHG) is a strong-field process in which one or several harmonic peaks in the HH spectrum are resonantly enhanced several times stronger than the neighboring harmonics. Resonant HHG is typically observed from transition metal plasma HH response. In our work, we address this interesting quantum phenomenon from theoretical point of view with the aid of first-principles method TD-CASSCF and TD-ORMAS. The atomic species of choice for this study are Mn and Mn⁺ where it has been found that the resonant enhancement occurs at 51 eV. The results from our work have allowed us to unambiguously identify the essential orbitals responsible for the resonant mechanism and the dominant transitions which underlie the resonant enhancement. Since we employ first-principles method, the results obtained in this work are expected to provide a reliable theoretical foundation for future researches on the topic of resonant HHG.