Photoionization in the time and frequency domain

Area of Science:

• Quantum mechanics
• Attosecond physics
• Atomic spectroscopy

Background:

• Ultrafast processes, like electron emission, are studied using attosecond (10^-18 s) extreme ultraviolet light pulses.
• Short pulse durations limit spectral resolution, complicating interpretation and comparison with theory.

Purpose of the Study:

• To determine photoionization time delays in neon atoms with high temporal and spectral resolution.
• To resolve discrepancies between experimental results and theoretical calculations in atomic photoionization.

Main Methods:

• An interferometric technique was employed to combine high temporal and spectral resolution.
• Photoionization time delays were measured across a 40-electron volt energy range in neon atoms.

Main Results:

• Direct ionization and ionization with shake-up were spectrally disentangled.
• Excellent agreement was achieved between experimental measurements and theoretical calculations.

Conclusions:

• The study successfully determined photoionization time delays in neon, resolving a 7-year-old puzzle.
• The findings validate theoretical models and enhance the understanding of ultrafast electron dynamics in atoms.