Theoretical Investigation of Strong Field Processes for Advancing Attosecond Chemistry

University Of Montana, Missoula MT

Investigators

Abstract

This research studies how electrons of an atom or molecule react to intense laser fields and to each other. Strong laser fields are used to study electron dynamics at the attosecond (10^-18 s) timescale for applications such as solar energy conversion and photosynthesis. Previous studies have assumed that only one electron is active in these systems. However, experiments have now shown that the interaction of many electrons, both with each other and with the field must be included. This project will attempt to include these effects. In addition, this project will provide two undergraduate students and one graduate student a broad array of theoretical and computational training. As part of the project, computations that yield useful information on attosecond chemistry will be incorporated into the curriculum for the undergraduate advanced physical chemistry class. Collaborations with experimentalists and quantum chemists involved in the project will contribute to building the connection between conventional spectroscopy and the emerging attosecond chemistry. The focus of this investigation will be the suppressed ionization of transition metal atoms vanadium, nickel, niobium, palladium, and tantalum in intense laser fields, and spectral features of high harmonic generation (HHG) for argon, nitrogen, and the molecule NO. The features include Cooper minima and HHG enhanced by resonances. There will be extensive benchmarking that consists of comparisons with published results and among different conditions, which will provide insight into the time-dependent density functional theory (TDDFT) approach and methods to improve it as well. The proposed study will render the most probable ion state, the form of the out-going electron wave function, and the time-dependent exchange and correlation potentials. This knowledge will lead to new understanding and improved modeling of strong field many-electron dynamics.