Dynamic Interference of Electrons

New generation of light sources and tremendous advances in high-order harmonic generation techniques allow to produce ultrashort laser pulses with the energy of a single-photon well above ionization threshold of any matter. These allow one to study quantum motions of electronic continuum states of matter exposed to a strong laser pulses. Particularly striking is the fundamental AC Stark shift that electronic eigenstates experience in the presence of oscillating external fields. We show that AC Stark effect in the continuum results in spectacular modification of the photoionization process. In particular it gives rise to a new fundamental effect of the dynamic interference between photoelectrons emitted at different times with a given kinetic energy. The effect causes enormous qualitative changes in the photoelectron spectrum and can easily be verified experimentally. Ab-initio theory exemplified by exact numerical calculations of the photoionization of hydrogen atom demonstrates that the dynamic interference is universal for a single-photon ionization processes by a high-frequency strong laser pulses.

Cooperations: Prof. Dr. L.S. Cederbaum (Universitat Heidelberg, Germany)
Status: in progress