Laser-Assisted Photoelectric Effect from Liquids

Area of Science:

• Surface science
• Quantum optics
• Physical chemistry

Background:

• The photoelectric effect is crucial for understanding electron emission.
• Investigating liquid surfaces presents unique challenges compared to solid surfaces.
• Laser-matter interactions offer advanced probes for surface phenomena.

Purpose of the Study:

• To report the first observation of the laser-assisted photoelectric effect from a liquid surface.
• To characterize the energy redistribution of photoelectrons emitted from water.
• To model the observed phenomena and understand electron emission dynamics from liquids.

Main Methods:

• Utilizing a liquid microjet of water under vacuum.
• Irradiating the liquid surface with 35.6 eV photons to generate photoelectrons.
• Dressing the photoelectrons with a 1.55 eV laser field.
• Employing energy-resolved measurements and theoretical modeling to third order.

Main Results:

• Observed the laser-assisted photoelectric effect on a liquid water surface.
• Detected sidebands in photoelectron energy spectra shifted by multiples of the laser photon energy (ℏω).
• The experimental results were consistent with third-order response modeling.

Conclusions:

• Demonstrated a novel method to study electron emission from liquid surfaces.
• The findings provide insights into the laser-assisted photoelectric effect at liquid-vacuum interfaces.
• This technique can be extended to investigate dynamics in liquid solutions and complex electron emission processes.