Two-dimensional infrared spectroscopy of vibrational polaritons
Two-dimensional infrared spectroscopy of vibrational polaritons
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DOI：
10.1073/pnas.1722063115
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发表时间：
2018-05-08
影响因子：
11.1
通讯作者：
Xiong, Wei
中科院分区：
文献类型：
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作者：
Xiang, Bo;Ribeiro, Raphael F.;Xiong, Wei
报道了相干光-物质激发-分子振动极化子的实验二维红外光谱。先进的二维红外光谱技术在振动极化子研究中的应用对我们在这两个领域的研究提出了挑战，也促进了我们对这两个领域的理解。首先，极化激子的二维红外光谱与自由非耦合激发的红外光谱有很大的不同，需要新的解释。其次，2D IR以一种状态选择性的方式独特地解决了混合光物质极化子和意外暗态的激发，揭示了它们之间原本隐藏的相互作用。此外，2D IR信号突出了分子非谐性的影响，这种影响几乎适用于所有分子体系。建立了同时考虑核非谐性和电非谐性的量子力学模型，为解释这类二维红外光谱提供了基础。这项工作为研究分子振动极化子的非线性光子学和化学现象奠定了基础，这是传统的线性光谱学无法探索的。
We report experimental 2D infrared (2D IR) spectra of coherent light-matter excitations-molecular vibrational polaritons. The application of advanced 2D IR spectroscopy to vibrational polaritons challenges and advances our understanding in both fields. First, the 2D IR spectra of polaritons differ drastically from free uncoupled excitations and a new interpretation is needed. Second, 2D IR uniquely resolves excitation of hybrid light-matter polaritons and unexpected dark states in a state-selective manner, revealing otherwise hidden interactions between them. Moreover, 2D IR signals highlight the impact of molecular anharmonicities which are applicable to virtually all molecular systems. A quantum-mechanical model is developed which incorporates both nuclear and electrical anharmonicities and provides the basis for interpreting this class of 2D IR spectra. This work lays the foundation for investigating phenomena of nonlinear photonics and chemistry of molecular vibrational polaritons which cannot be probed with traditional linear spectroscopy.