Potential barrier effects in two-photon ionization processes

Potential barrier effects in two-photon ionization processes

Time delays in two-photon ionization.

We present results of ab initio numerical simulations of time delays in two-photon ionization of the helium atom using the attosecond streaking technique. The temporal shifts in the streaking traces consist of two contributions, namely, a time delay acquired during the absorption of the two photons from the extreme-ultraviolet field and a time delay accumulated by the photoelectron after photoa...

0 Twist - three effects in two - photon processes

We give a general treatment of twist-three effects in two-photon reactions. We address the issue of the gauge invariance of the Compton amplitude in generalized Bjorken kinematics and relations of twist-three 'transverse' skewed parton distributions to twist-two ones and interaction dependent three-particle correlation functions. Finally, we discuss leading order evolution of twist-three functi...

Anisotropy parameters in two-color two-photon above-threshold ionization

Direct two-photon double ionization of helium

The role of electron correlation, i.e. the electron-electron repulsion, in non-sequential two-photon double ionization of helium has been widely debated in literature, and the issue is not yet fully resolved. We present total cross sections for this process obtained within a one dimensional model of the helium atom. In our calculations the cross sections are obtained in two ways. Firstly, the t...