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

• Applicant: Privatdozent Dr. Josef Tiggesbäumker, Ph.D.
• Subject Area: Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
• Term: from 2018 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 392530662

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.

• DFG Programme: Research Grants