Spatiotemporal imaging of valence electron motion

Area of Science:

• Quantum mechanics
• Ultrafast spectroscopy
• Molecular imaging

Background:

• Electron motion on the (sub-)femtosecond timescale is crucial for phenomena like phase transitions and chemical reactions.
• Static electron densities are imageable, but real-time electron motion requires ultrafast techniques.
• Current methods have limitations in imaging electron dynamics within molecules.

Purpose of the Study:

• To demonstrate an all-optical approach for imaging ultrafast valence electron wave packets in real-time.
• To achieve a time resolution of a few femtoseconds for observing electron motion.
• To overcome limitations of existing laser-induced orbital imaging techniques.

Main Methods:

• Utilizing an all-optical pump-probe-deflect scheme.
• Preparing an ultrafast wave packet through strong-field ionization.
• Directly imaging charge oscillations in the residual ion.

Main Results:

• Successful imaging of an ultrafast valence electron wave packet in real-time.
• Achieved a time resolution of a few femtoseconds.
• Demonstrated a novel method for observing electron dynamics.

Conclusions:

• The developed all-optical approach enables real-time imaging of electron wave packets.
• This technique offers femtosecond resolution for studying ultrafast electron motion.
• Potential to enable real-time imaging of photoionization dynamics, including charge migration and transfer.