Droppelmann G, Bünermann O, Schulz C P, Stienkemeier F
Universität Bielefeld, Universitätsstrasse 25, D-33615 Bielefeld, Germany.
Phys Rev Lett. 2004 Jul 9;93(2):023402. doi: 10.1103/PhysRevLett.93.023402.
Nanodroplets of either superfluid 4He or normal fluid 3He are doped with Rb atoms that are bound to the surface of the droplets. The formation of RbHe exciplexes upon 5P(3/2) excitation is monitored in real time by femtosecond pump-probe techniques. We find formation times of 8.5 and 11.6 ps for Rb 4He and Rb 3He, respectively. A comparison to calculations based on a tunneling model introduced for these systems by Reho et al. [J. Chem. Phys. 113, 9694 (2000)]] shows that the proposed mechanism cannot account for our findings. Apparently, a different relaxation dynamics of the superfluid opposed to the normal fluid surface is responsible for the observed formation times.
超流4He或正常流体3He的纳米液滴掺杂有与液滴表面结合的Rb原子。通过飞秒泵浦-探测技术实时监测5P(3/2)激发时RbHe激基复合物的形成。我们发现Rb 4He和Rb 3He的形成时间分别为8.5皮秒和11.6皮秒。与基于Reho等人[《化学物理杂志》113, 9694 (2000)]为这些系统引入的隧穿模型的计算结果进行比较表明，所提出的机制无法解释我们的发现。显然，超流体与正常流体表面不同的弛豫动力学是导致观察到的形成时间的原因。
