Lifetime dynamics of plasmons in the few-atom limit
Lifetime dynamics of plasmons in the few-atom limit
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DOI：
10.1073/pnas.1805357115
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发表时间：
2018-09-11
影响因子：
11.1
通讯作者：
Halas, Naomi J.
中科院分区：
文献类型：
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作者：
Chapkin, Kyle D.;Bursi, Luca;Halas, Naomi J.
多环芳烃（PAH）分子基本上是亚纳米极限的石墨烯，通常由50个或更少的原子组成。通过添加或移除单个电子，这些分子可以支持光谱的可见区域中的分子等离子体（集体）共振。在这里，我们探测在这些量子系统中的等离子体动力学通过测量三个带负电荷的PAH分子的激发态寿命：蒽，苯并[ghi]二萘嵌苯，和二萘嵌苯。与处于中性状态的分子相比，这三个系统由于通过分子等离子体激元“退相”和振动弛豫的多个电子-空穴对的去激发而表现出快得多的衰减动力学。这项研究提供了一个在纯量子极限的集体和单电子激发动力学之间的区别，并介绍了一个概念框架，可视化分子等离子体衰变。
Polycyclic aromatic hydrocarbon (PAH) molecules are essentially graphene in the subnanometer limit, typically consisting of 50 or fewer atoms. With the addition or removal of a single electron, these molecules can support molecular plasmon (collective) resonances in the visible region of the spectrum. Here, we probe the plasmon dynamics in these quantum systems by measuring the excited-state lifetime of three negatively charged PAH molecules: anthanthrene, benzo[ghi]perylene, and perylene. In contrast to the molecules in their neutral state, these three systems exhibit far more rapid decay dynamics due to the deexcitation of multiple electron-hole pairs through molecular plasmon "dephasing" and vibrational relaxation. This study provides a look into the distinction between collective and single-electron excitation dynamics in the purely quantum limit and introduces a conceptual framework with which to visualize molecular plasmon decay.