Anisotropic dynamics of two-photon ionization: An attosecond movie of photoemission

TL;DR

This paper demonstrates a method to visualize the full angle-dependent dynamics of photoemission in helium with attosecond resolution, revealing detailed space-time-energy evolution of the photoelectron wavepacket.

Contribution

It introduces spectrally- and angularly-resolved attosecond interferometry to decode complex photoemission dynamics, enabling complete reconstruction of the photoelectron wavepacket.

Findings

Reconstructed the space-time-energy evolution of photoemission.

Decoded the complex transition probability amplitude.

Achieved full imaging of photoemission dynamics in helium.

Abstract

Imaging in real time the complete dynamics of a process as fundamental as photoemission has long been out of reach due to the difficulty of combining attosecond temporal resolution with fine spectral and angular resolutions. Here, we achieve full decoding of the intricate angle-dependent dynamics of a photoemission process in helium, spectrally and anisotropically structured by twophoton transitions through intermediate bound states. Using spectrally- and angularly-resolved attosecond electron interferometry, we characterize the complex-valued transition probability amplitude towards the photoelectron quantum state. This allows reconstructing in space, time and energy the complete formation of the photoionized wavepacket.