Quantitative Inspection of the Transient Quasiparticle Picture on the Coherent Phonon Generation Mechanism

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K05121
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Condensed matter physics I
• Research Institution: University of Tsukuba
• Principal Investigator: HINO Ken-ichi 筑波大学, 数理物質系, 教授 (90228742)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: コヒーレントフォノン / 超短パルスレーザー / 超高速過程 / ファノ共鳴 / プラズモン－フォノン相互作用 / ラビ振動 / ボゾン化法 / 非線形光学過程

Outline of Final Research Achievements

Coherent Phonon (CP) is one of the representative ultrafast phenomena generated by the irradiation of ultrashort pulse lasers on semiconductors. This study is aimed at understanding the underlying physics of CP in the early time region that has still remained unexplored; this is the time region extended till approximately 100 fs after the irradiation of the pulse laser. The non-perturbative theoretical model with respect to the intensity of irradiated pulse laser is constructed, and is applied to the present physical system to understand the generation mechanism of CP. Further, we obtain the following results as manifestation of a transient Fano effect, irregular oscillatory patterns of CP time signals due to a resonant coupling between plasmon and longitudinal-optical phonon and asymmetric spectral profiles in the associated CP spectra, a Rabi-oscillatory pattern of CP initial phases, and so on. These results are in harmony with experimental ones.

Free Research Field

光物性理論