Attosecond Imaging of Electronic Wave Packets

Area of Science:

• Quantum mechanics
• Atomic physics
• Ultrafast spectroscopy

Background:

• Electronic wave packets exhibit both temporal and spatial evolution due to delocalized electronic states.
• Spatial evolution of wave packets has been experimentally inaccessible on the attosecond timescale.
• Understanding electron dynamics is crucial for fields like materials science and quantum computing.

Purpose of the Study:

• To develop and apply a novel experimental technique to probe the spatial dynamics of electronic wave packets.
• To investigate the attosecond-scale spatial evolution and dynamics of hole density in heavy atomic cations.
• To capture the ultrafast charge dynamics and wave packet motion in krypton and xenon.

Main Methods:

• Development of a phase-resolved two-electron-angular-streaking method.
• Application of the technique to study krypton and xenon cations.
• Attosecond time-resolved imaging of electronic wave packet spatial evolution.

Main Results:

• The spatial evolution of an ultrafast spin-orbit wave packet in the krypton cation was imaged.
• The motion of an even faster wave packet in the xenon cation was captured for the first time.
• An electronic hole in xenon was observed to refill 1.2 femtoseconds after its creation, with filling occurring on the opposite side of its birth.

Conclusions:

• The developed method provides unprecedented access to the spatial dynamics of electronic wave packets at the attosecond timescale.
• Ultrafast charge dynamics, including hole refilling and spatial wave packet motion, can be precisely imaged in heavy atoms.
• This work opens new avenues for exploring fundamental electron behavior in atoms and molecules.