Attosecond probing of photoionization dynamics from diatomic to many-atom molecules

The natural diversity of molecules in terms of geometries, chemical properties, work functions, among others, offers an impressive laboratory for observing fundamental electron dynamics down to the attosecond timescale. Here, we use some recent angularly resolved Wigner time delay measurements performed in our attoscience laboratory in Lyon to illustrate the electron dynamics in molecules containing a few (N-2, C2H2, and C2H4) to many atoms (C10H8 and C10H16). In the few-atom case, the Wigner delay can be measured for a particular electronic state. This allows us to identify the underlying physical mechanisms governing photoionization processes, such as the well-known shape resonance in valence-ionized nitrogen molecule. Promising new experimental results using angle-resolved photoelectron spectroscopy on ethylene show a tendency in the ionization time delay between the X and A states. As a perspective, we show that for many-atom molecules (C-60 and C10Hx, with x = 8 or 16), the photoionization metrology can address different kinds of electron dynamics with a collective behavior.

Automated summary

The natural diversity of molecules provides an excellent platform for studying electron dynamics, and recent Wigner time delay measurements have shed light on the behavior of electrons in molecules of different sizes. These measurements have helped identify the physical mechanisms behind photoionization processes and have revealed interesting trends in ionization time delays. Furthermore, studies on larger molecules have shown that photoionization metrology can reveal collective electron behaviors.