Institute of Experimental Physics, Graz University of Technology, Petersgasse 16, A-8010 Graz, Austria.
Phys Chem Chem Phys. 2011 Nov 14;13(42):18781-8. doi: 10.1039/c1cp21280j. Epub 2011 Jul 25.
The preparation of an artificial superatom consisting of a positive charge inside a superfluid helium nanodroplet and an electron in an orbital surrounding the droplet is of fundamental interest and represents an experimental challenge. In this work, nanodroplets of several thousand helium atoms are doped with single caesium (Cs) atoms. While on the droplet, the Cs valence electron is excited in two steps through an intermediate state into nS, nP, and nD states. The excitation is monitored by laser induced fluorescence or, for high principal quantum numbers, by resonant three-photon-ionization. On-droplet Rydberg excitations are resolved up to about n = 20. The energies are compared with those of free Cs atom Rydberg states and quantum defects as well as the on-droplet ionization threshold are derived.
由超流氦纳米液滴中的正电荷和围绕液滴的轨道中的电子组成的人工超原子的制备具有重要的意义，同时也代表了一项实验挑战。在这项工作中，数千个氦原子的纳米液滴中掺杂了单个铯（Cs）原子。在液滴上，通过中间态将 Cs 价电子分两步激发到 nS、nP 和 nD 态。通过激光诱导荧光或对于高主量子数，通过共振三光子电离来监测激发。在液滴上分辨出高达约 n = 20 的里德伯激发。将能量与自由 Cs 原子里德伯态的能量以及量子亏损进行比较，并得出了液滴上的电离阈值。
