摘要
We performed real-time and real-space numerical simulations of high-order harmonic generation in the threedimensional structured molecule methane(CH_(4)) using time-dependent density functional theory. By irradiating the methane molecule with an elliptically polarized laser pulse polarized in the x–y plane, we observed significant even-order harmonic emission in the z-direction. By analyzing the electron dynamics in the electric field and the multi-orbital effects of the molecule, we revealed that electron recombination near specific atoms in methane is the primary source of highorder harmonic generation in the z-direction. Furthermore, we identified the dominant molecular orbitals responsible for the enhancement of harmonics in this direction and demonstrated the critical role played by multi-orbital effects in this process.
基金
Project supported by the National Natural Science Foundation of China (Grant No. 12204214)
the National Key Research and Development Program of China (Grant No. 2022YFE0134200)
the Fundamental Research Funds for the Central Universities (Grant No. GK202207012), QCYRCXM-2022-241
the Guangdong Basic and Applied Basic Research Foundation (Grant No. 2025A1515011117)。
