Probing single-photon ionization on the attosecond time scale

TL;DR

This paper investigates the ultrafast dynamics of argon atom photoionization on the attosecond scale, measuring time delays between electrons emitted from different shells using interferometric techniques and accounting for measurement interactions.

Contribution

It introduces a method to accurately measure single-photon ionization delays on the attosecond timescale, including the effects of the probing infrared field.

Findings

Measured time delays between 3s and 3p electrons in argon

Developed a universal correction formula for measurement interactions

Demonstrated the importance of measurement process in delay determination

Abstract

We study photoionization of argon atoms excited by attosecond pulses using an interferometric measurement technique. We measure the difference in time delays between electrons emitted from the $3s^2$ and from the $3p^6$ shell, at different excitation energies ranging from 32 to 42 eV. The determination of single photoemission time delays requires to take into account the measurement process, involving the interaction with a probing infrared field. This contribution can be estimated using an universal formula and is found to account for a substantial fraction of the measured delay.