The impact of the carrier envelope phase -- dependence on system and laser parameters

TL;DR

This study uses quantum-mechanical simulations to explore how the Carrier-Envelope Phase influences electron emission asymmetries in different atomic and cluster systems under ultra-short laser pulses.

Contribution

It provides a comparative analysis of system-dependent effects on CEP-induced electron emission asymmetries using TDDFT simulations.

Findings

Electron emission asymmetry depends strongly on the system's spectral response.

Ponderomotive motion and dynamical polarization interplay influence the results.

System dependence varies between atomic and cluster targets.

Abstract

We investigate, from a theoretical perspective, photo-emission of electrons induced by ultra-short infrared pulses covering only a few photon cycles. In particular, we investigate the impact of the Carrier-Envelope Phase (CEP) of the laser pulse which plays an increasingly large role for decreasing pulse length. As key observable we look at the asymmetry of the angular distribution as function of kinetic energy of the emitted electrons. The focus of the present study lies on the system dependence of the reaction. To this end, we study two very different systems in comparison, an Ar atom and the Na9+ cluster. The study employs a fully quantum-mechanical description of electron dynamics at the level of Time-Dependent Density Functional Theory (TDDFT). We find a sensitive dependence on the system which can be related to the different spectral response properties. Results can be understood from an interplay of the ponderomotive motion driven by the external photon field and dynamical polarization of the system.