Excitonic couplings and interband energy transfer in a double-wall molecular aggregate imaged by coherent two-dimensional electronic spectroscopy
Excitonic couplings and interband energy transfer in a double-wall molecular aggregate imaged by coherent two-dimensional electronic spectroscopy
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DOI：
10.1063/1.3197852
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发表时间：
2009-08-07
影响因子：
4.4
通讯作者：
Kauffmann, H. F.
中科院分区：
文献类型：
--
作者：
Milota, F.;Sperling, J.;Kauffmann, H. F.
采用二维相干电子光谱技术，研究了室温下C_8O_3多带双管菁染料聚集体的早期分子激子及其量子动力学行为.次20 fs的测量提供了一个直接的外观到基本的电子耦合的细节，通过扩展到两个频率轴的光谱转换。在发射（ω（3））-吸收（ω（1））二维频率空间中，重相（k（I）=-k（1）+k（2）+k（3））和非重相（k（II）=+k（1）-k（2）+k（3））数据的相关谱将带间激子成像为交叉峰信号，并揭示了激子弛豫的量子耗散机制。交叉峰的光谱条纹直接揭示了管到管能量转移的道路上的带间失相和激子布居弛豫，而无需求助于先验模型。理论和模拟，基于一个有效的多能级方案和量子耗散模型与实验脉冲包络，解释交叉峰的起源，揭示潜在的电子跃迁序列，恢复条纹图案松弛交叉峰沿着Ω（1），并重建电子激发流的空间能量路径。
The early stage of molecular excitonics and its quantum-kinetic dynamics in the multiband, bitubular cyanine dye aggregate C8O3 at room temperature are revealed by employing two-dimensional (2D) coherent electronic spectroscopy in the visible spectral region. The sub-20 fs measurements provide a direct look into the details of elementary electronic couplings by spreading spectroscopic transitions into two frequency axes. Correlation spectra of rephasing (k(I)=-k(1)+k(2)+k(3)) and nonrephasing (k(II)=+k(1)-k(2)+k(3)) data in emission (omega(3))-absorption (omega(1)) 2D-frequency space image interband excitons into cross-peak signals and unveil the quantum-dissipative regime of exciton relaxation. Spectral streaking of cross peaks directly reveals interband dephasing and exciton population relaxation on the road to tube-to-tube energy transfer without making recourse to an a priori model. Theory and simulations, based on an effective multilevel scheme and a quantum-dissipative model with experimental pulse envelopes, explain the origin of the cross peaks, reveal the underlying sequences of electronic transitions, recover the streaking patterns of relaxing cross peaks along omega(1), and reconstruct the space-energy pathways of electronic excitation flow.