论文标题
通过在笔离子化碰撞中对离子和电子的重合检测直接观察feshbach-resonance
Direct Observation of a Feshbach-resonance by Coincidence-detection of Ions and Electrons in Penning Ionization Collisions
论文作者
论文摘要
观察具有量子状态分辨率的分子动力学是化学物理学的主要挑战之一。碰撞动力学的完全表征会导致微观理解和对不同量子现象（例如散射共振）的理解。我们提出了一种新的实验方法，用于观察涉及中性颗粒和离子的分子动力学，该动力学能够提供动力学的状态对状态映射。我们使用氩和亚稳态氦之间的笔球电离反应来产生氩离子和基状态氦原子对在几个埃埃斯特罗姆的分离时。弹出电子的能量传递有关离子初始电子状态的信息。离子产物的巧合检测提供了对后离子 - 离子中性动力学的状态解决的描述。我们证明了电子和离子能谱之间的相关性使我们能够直接观察到$^+$的旋转轨道激发的feshbach共振状态。我们测量了准结合的$^+$ a $ _2 $状态的寿命，并讨论了我们方法的可能应用。
Observation of molecular dynamics with quantum state resolution is one of the major challenges in chemical physics. Complete characterization of collision dynamics leads to the microscopic understanding and unraveling of different quantum phenomena such as scattering resonances. We present a new experimental approach for observing molecular dynamics involving neutral particles and ions that is capable in providing state-to-state mapping of the dynamics. We use Penning ionization reaction between argon and metastable helium to generate argon ion and ground state helium atom pairs at separation of several angstroms. The energy of ejected electron carries the information about the initial electronic state of an ion. The coincidence detection of ionic products provides a state resolved description of the post-ionization ion-neutral dynamics. We demonstrate that correlation between the electron and ion energy spectra enables us to directly observe the spin-orbit excited Feshbach resonance state of HeAr$^+$. We measure the lifetime of the quasi-bound HeAr$^+$ A$_2$ state and discuss possible applications of our method.
