Polarization spectroscopy of gaseous tropolone in a strong electric field.
Polarization spectroscopy of gaseous tropolone in a strong electric field.
复制标题
强电场中气态托酚酮的偏振光谱。
作者：
Chengyin Wu;Yonggang He;W. Kong
本文报道了用共振增强多光子电离方法研究强电场中的环庚三酚酮气体的偏振光谱。电场诱导隧穿质子在两个等效氧原子之间的局部化。结果，分子框架的C2 v对称性被破坏，并且宇称选择规则被违反。场诱导跃迁是A型的，跃迁偶极子垂直于无场条件下的跃迁偶极子。极化比，即，因此，在共振激光的不同偏振下的总激发产额的比率偏离纯B型跃迁的比率。在60 kV/cm的电场中，实验极化比意味着B型和A型跃迁的混合基本相等。此外，诱导跃迁与两个无场子带重叠，并且两个子带之间的强度比表现出对所施加的电场的依赖性。这些观测结果可以定性建模使用量子力学的方法，假设一个两级系统。一个令人困惑的结果是诱导跃迁的跃迁偶极子的大小，这被证明是基本上线性依赖于所施加的电场。
We report studies of polarization spectroscopy of gaseous tropolone in a strong electric field using resonantly enhanced multiphoton ionization. The electric field induces localization of the tunneling proton between the two equivalent oxygen atoms. As a result, the C2v symmetry of the molecular frame is broken, and the parity selection rule is violated. The field induced transitions are type A with transition dipoles perpendicular to those under field free conditions. The polarization ratios, i.e., the ratios of the overall excitation yield under different polarizations of the resonant laser, thus deviate from those of a pure type B transition. In a field of 60 kV/cm, the experimental polarization ratio implies an essentially equal mixture of type B and type A transitions. Moreover, the induced transitions overlap with the two field-free subbands, and the resulting intensity ratios between the two subbands demonstrate dependence on the applied electric field. These observations can be qualitatively modeled using a quantum mechanical approach by assuming a two level system. A puzzling result is the magnitude of the transition dipole of the induced transition, which is proven to be essentially linearly dependent on the applied electric field.