Zhu Ruidan, Zou Jiading, Wang Zhuan, Chen Hailong, Weng Yuxiang
Beijing National Laboratory for Condensed Matter Physics, Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
J Phys Chem A. 2020 Nov 12;124(45):9333-9342. doi: 10.1021/acs.jpca.0c06559. Epub 2020 Nov 2.
The difference between the excited- and ground-state vibrational wavepackets remains to be fully explored when multiple vibrational modes are coherently excited simultaneously by femtosecond pulses. In this work, we present a series of one- and two-dimensional electronic spectroscopy for studying multimode wavepackets of oxazine 720 in solution. Fourier transform (FT) maps combined with time-frequency transform (TFT) are employed to unambiguously distinguish the origin of low-frequency vibrational wavepackets, that is, an excited-state vibrational wavepacket of 586 cm with a dephasing time of 0.7 ps and a ground-state vibrational wavepacket of 595 cm with a dephasing time of 1.3-1.7 ps. We also found the additional low-frequency vibrational wavepackets resulting from the coupling of the 595 cm mode to a series of high-frequency modes centered at 1150 cm via electronic transitions. The combined use of FT maps and TFT analysis allows us to reveal the potential vibrational coupling of wavepackets and offers the possibility of disentangling the coupling between the electronic and vibrational degrees of freedom in condensed-phase systems.
当飞秒脉冲同时相干激发多个振动模式时，激发态和基态振动波包之间的差异仍有待充分探索。在这项工作中，我们展示了一系列用于研究溶液中恶嗪720多模波包的一维和二维电子光谱。傅里叶变换（FT）图与时频变换（TFT）相结合，用于明确区分低频振动波包的起源，即一个相位失配时间为0.7 ps的586 cm激发态振动波包和一个相位失配时间为1.3 - 1.7 ps的595 cm基态振动波包。我们还发现了由595 cm模式通过电子跃迁与一系列以1150 cm为中心的高频模式耦合产生的额外低频振动波包。FT图和TFT分析的联合使用使我们能够揭示波包潜在的振动耦合，并为解开凝聚相系统中电子和振动自由度之间的耦合提供了可能性。
