Nanomatrix Effects in der Ultrafast Ionisation Dynamics of Clusters in Superfluid Helium Droplets

双色脉冲等强激光场对物质的相位控制激发，为研究甚至控制电子运动在自然时间尺度上的非线性动力学开辟了一条途径。尖端，特别是团簇是研究这些过程的有希望的纳米尺度对象，因为除了局部场增强或集体电子运动外，目标的尺寸（直径团簇更小/与激光波长相当）也起着重要作用。该项目的核心是氦纳米液滴中的团簇，而相敏电子能谱（PoP）则应用于以最高时间分辨率研究复杂环境中团簇动态的影响。PoP光谱从实验光谱中提取相干信号是该方法的明显优势。像超流氦液滴中的团簇这样的多体系统的新组合允许研究(i)环境中的强场诱导电离动力学，而且（ii）对玻色-爱因斯坦凝聚现象的另一种途径。我们建议用PoP光谱来确定量子漩涡形成的临界尺寸，为有限系统的超流动性问题提供新的贡献。

The excitation of matter with intense and phase-controlled laser fields like two-color pulses opens up a route to study and even control the non-linear dynamics on the natural time scale of the electron motion. Tips and in particular clusters are promising nanoscale objects to study such processes since beside local field enhanced or collective electron motion also the dimensions of the target (diameter cluster smaller/ comparable to laser wavelength) plays a significant role. Central to this project are clusters in helium nanodroplets, whereas phase-sensitive electron spectroscopy (phase-of-the-phase, PoP) is applied to study the impact on the dynamic of clusters in a complex environment at the highest time resolution. The fact that PoP spectroscopy extracts the coherent signals from the experimental spectra is a clear advantage of method.The novel combination of a many-body system like a cluster in a superfluid helium droplet allows to investigate (i) the strong-field induced ionization dynamics in an environment but also (ii) an alternative access to the phenomenon of Bose-Einstein condensation. We propose to determine the critical size for the formation of quantum vortices by PoP spectroscopy providing new contributions to the topic of superfluidity in finite systems.