In quantum mechanics,when an electron is quickly ripped off from a molecule,a superposition of new eigenstates of the cation creates an electron wave packet that governs the charge flow inside,which has been called ch...In quantum mechanics,when an electron is quickly ripped off from a molecule,a superposition of new eigenstates of the cation creates an electron wave packet that governs the charge flow inside,which has been called charge migration(CM).Experimentally,extracting such dynamics at its natural(attosecond)timescale is quite difficult.We report the first such experiment in a linear carbon-chain molecule,butadiyne(C_(4)H_(2)),via high-harmonic spectroscopy(HHS).By employing advanced theoretical and computational tools,we showed that the wave packet and the CM of a single molecule are reconstructed from the harmonic spectra for each fixed-in-space angle of the molecule.For this onedimensional molecule,we calculate the center of charge <x>(t) to obtain v_(cm),to quantify the migration speed and how it depends on the orientation angle.The findings also uncover how the electron dynamics at the first few tens to hundreds of attoseconds depends on molecular structure.The method can be extended to other molecules where the HHS technique can be employed.展开更多
基金supported by the National Key Research and Development Program of China (No. 2019YFA0308300)the National Natural Science Foundation of China (Nos. 91950202, 12225406, 12074136, 12021004, and 11934006)+2 种基金the Natural Science Foundation of Hubei Province (No. 2021CFB330)supported by the Chemical Sciences, Geosciences, and Biosciences Division, Office of Basic Energy Sciences, Office of Science, U.S. Department of Energy (No. DE-FG0286ER13491)supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences (No. DE-SC0023192)
文摘In quantum mechanics,when an electron is quickly ripped off from a molecule,a superposition of new eigenstates of the cation creates an electron wave packet that governs the charge flow inside,which has been called charge migration(CM).Experimentally,extracting such dynamics at its natural(attosecond)timescale is quite difficult.We report the first such experiment in a linear carbon-chain molecule,butadiyne(C_(4)H_(2)),via high-harmonic spectroscopy(HHS).By employing advanced theoretical and computational tools,we showed that the wave packet and the CM of a single molecule are reconstructed from the harmonic spectra for each fixed-in-space angle of the molecule.For this onedimensional molecule,we calculate the center of charge <x>(t) to obtain v_(cm),to quantify the migration speed and how it depends on the orientation angle.The findings also uncover how the electron dynamics at the first few tens to hundreds of attoseconds depends on molecular structure.The method can be extended to other molecules where the HHS technique can be employed.
