2023 Fiscal Year Annual Research Report
Ultrafast femtosecond laser control of electron dynamics in two-dimensional strong spin-orbit coupling materials
| Project/Area Number |
22K13991
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| Research Institution | The University of Tokyo |
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Principal Investigator |
Hashmi Arqum 東京大学, 大学院工学系研究科(工学部), 特任研究員 (90815325)
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| Project Period (FY) |
2022-04-01 – 2024-03-31
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| Keywords | Spin-orbit interactions / TDDFT / Nonlinear optics / Ultrafast |
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| Outline of Annual Research Achievements |
Our objective wass to explore the possibility of controlling ultrafast dynamics in WSe2 and Toplogical insulator Bi2Se3 by using time-dependent density functional theory (TDDFT) and Maxwell equations.
Two-Color Pulses: We studied the intensity ratio between a few-cycle pulse of an ω and 2ω laser in WSe2. We found that a two-color field enhances valley polarization by up to 1.2 times larger than a single-color pulse. The intensity ratio and the relative phase are the most crucial factors.
Topological insulator:I have explored the bulk and surface state by weak and strong field response in Bi2Se3. Our results demonstrate that a linearly polarized resonant pulse generates higher oder odd harmonics by strong field. The strength of harmonics in bulk Bi2Se3 is higher than in the layered system.
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