Observation of vibrational overtones by single-molecule resonant photodissociation.
Observation of vibrational overtones by single-molecule resonant photodissociation.
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DOI：
10.1038/ncomms8825
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发表时间：
2015-07-22
影响因子：
16.6
通讯作者：
Brown KR
中科院分区：
文献类型：
--
作者：
Khanyile NB;Shu G;Brown KR
通过交感冷却，分子离子可以保持在激光冷却的原子离子链中。该系统是理想的执行高精度分子光谱与应用在天体化学和基础物理。在这里，我们展示了同样的系统可以与宽带激光相结合，以发现新的分子跃迁。我们使用Ca+和CaH+的三离子链，通过Ca+荧光检测共振增强的多光子解离来观察振动跃迁。在理论计算的基础上，我们将观测到的峰分配给从基底振动状态ν=0到ν=9和10的过渡。我们的方法允许我们跟踪单分子事件，并且它可以扩展到任何分子，通过使用正常模式频率位移来检测解离。这种测量光谱学是分子离子控制所需的精密光谱学的桥梁。研究分子的光谱通常需要大量的样本，这对于难以产生的离子来说是很难实现的。在这里，作者获得了三离子哥伦比亚晶体中单个CaH+分子的光谱，观察到新的分子跃迁。
Molecular ions can be held in a chain of laser-cooled atomic ions by sympathetic cooling. This system is ideal for performing high-precision molecular spectroscopy with applications in astrochemistry and fundamental physics. Here we show that this same system can be coupled with a broadband laser to discover new molecular transitions. We use three-ion chains of Ca+ and CaH+ to observe vibrational transitions via resonance-enhanced multiphoton dissociation detected by Ca+ fluorescence. On the basis of theoretical calculations, we assign the observed peaks to the transition from the ground vibrational state, ν=0 to ν=9 and 10. Our method allows us to track single-molecular events, and it can be extended to work with any molecule by using normal mode frequency shifts to detect the dissociation. This survey spectroscopy serves as a bridge to the precision spectroscopy required for molecular ion control. Studying the spectra of molecules typically requires large samples, which can be difficult to achieve for hard-to-generate ions. Here, the authors obtain spectra from single CaH+ molecules in a three-ion Columbic crystal, observing new molecular transitions.