Dr. Stefan Pabst
Harvard-Smithsonian Center for Astrophysics
Multi-orbital dynamics on the attosecond timescale
Strong-field and ultrashort pulses offer unique opportunities to trigger and probe electronic motion in multi-electron systems. After and during ionization, the question remains: what is the state of the parent ion?
Depending on the details of the pulse, the answer can change significantly. Attosecond photoionization, for instances, may lead to ultrafast decoherence within the ion; a phenomenon often overlooked when preparing hole wavepackets. With attosecond transient absorption spectroscopy we can nowadays access these coherences and probe them with unprecedented resolution.
A promising way to generate coherent hole motion in atoms and molecules is strong-field ionization. In krypton and xenon, we studied the details of the hole generation process during tunnel ionization. Our findings show a complicated sub-cycle behavior in the ionic phases and populations, improve our understanding of strong-field induced motion in many-body systems, and may pave the way for strong-field-driven charge-transfer dynamics.