Characterizing multielectron dynamics during recollision

TL;DR

This paper demonstrates a method to directly measure multielectron dynamics during electron recollision using in situ techniques, revealing the influence of plasmonic resonances and advancing attosecond science.

Contribution

It introduces in situ measurement methods to isolate multielectron effects during recollision, supported by experiments, simulations, and semi-classical theory.

Findings

Measured group delay caused by plasmonic resonance in Xe

Simulated spectral phase of recollision electrons in C$_{60}$

Proposed in situ techniques with 300 eV electrons for ultimate time resolution

Abstract

Measuring the delay for an electron to emerge from different states is one of the major achievements of attosecond science. This delay can have two origins - the electron wave packet is reshaped during departure by the electrostatic field of the ionizing medium or it is modified by dynamic interaction with the remaining electrons. Most experiments have observed the former, but confirmation requires a complex calculation. A direct measurement of multielectron dynamics is needed. Photo-recombination - the inverse of photoionization - occurs naturally during electron recollision and can be measured by combining a perturbing beam to modify the recollision electron before recombination. These in situ methods allow us to unambiguously isolate multielectron dynamics - the reference being the spectral phase of an attosecond pulse simultaneously measured in spectral regions without multielectron interaction. Here, we measure the group delay of the recollision electron caused by plasmonic resonance dynamics in Xe, simulate the in situ measured spectral phase of a recollision electron generated in the presence of the plasmonic resonance in C$_{60}$ and present a corresponding semi-classical theory based on the strong-field approximation. Our results suggest that in situ techniques, together with 300 eV recollision electrons, will allow the ultimate time response of electronic matter to be measured.