Speaker: Guizhong Zhang, Tianjin University, China

Title: Vortex Momentum Distribution in Hydrogen

Abstract: This presentation will start with a brief introduction to Tianjin University of China. Following that, the talk will be concerned with attosceond and strong-field physics. As is well known for a few-cycle attosecond light pulse, the carrier envelope phase (CEP) has a direct and significant impact on its electric field and strong field processes induced by isolated attosecond pulse (IAP). By numerically investigating the angular photoelectron momentum spectra generated by overlapping IAP and infrared (IR) pulses, we show a scheme for retrieving the CEP value through the rotation angle of the momentum pattern. Another interesting observation for momentum distributions is their vortex shape created and experimentally corroborated by two time-delayed and oppositely circularly polarized attosecond pulses. We also report our numerical experiments on the formation of the vortex momentum distributions and their symmetry distortion when the dynamic Stark effect is taken into account. All the simulation has been performed by deploying the strong field approximation (SFA) theory and on hydrogen atom which has an analytical expression for the dipole transition matrix element.

Coffee/tea and cake from 15:00