RUI: Double Photoionization to Probe Electron Correlation in Atomic and Molecular Systems with More than Two Electrons

California Maritime Academy, Vallejo CA

Investigators

Abstract

Some of the simplest objects making up the world as we experience it on a day-to-day basis are atoms and molecules. These atoms and molecules consist of nuclei made up of protons and neutrons surrounded by a sea of electrons. Interactions among atoms and molecules, especially chemical interactions, involve the motion of the electrons. Exploring the dynamics of this motion, leading to interactions, has been a major focus of research since the discovery of quantum mechanics, whose laws allow us to calculate this motion. When an atom or molecule consists of a large number of electrons, the calculations can only be approximate and are extremely difficult, while at the same time being important for understanding aspects of chemistry. This project will focus on calculating a subset of these interactions. The research will be carried out at an undergraduate institution, offering the possibility of a true research experience for undergraduate students. This project will examine the consequences of correlated electron dynamics of small atoms and molecules with more than two electrons in order to better understand the similarities and differences in different target atoms and molecules that result from having many electrons. Electron correlation is a fundamental phenomena with great impacts on the behavior and structure of all matter. Many decades of research towards developing more accurate ways of accounting for the non-approximated dynamics of electronic motion in even the simplest atoms and molecules have been focused on bound states (energy levels of atoms, potential curves of molecules, etc.) but the consequences of this correlation also greatly impact the resulting double continua when two electrons are ejected from a target by photons. These correlated electron interactions are fundamental to the organization and structure of matter at the atomic level and continue to be of vital importance to study and better understand. Broader consequences of pursuing more a complete understanding of electron correlation in simple atoms and molecules with more than two electrons would impact many other fields of study, including chemistry, atomic and molecular physics, molecular biology, and material science, to name a few. This project will investigate the impacts of these fundamental electronic correlations for non-trivial atoms and molecules with more than two electrons in order to better understand the ways that the initial and final states of the electrons that remain bound to the atom or diatomic molecule can affect the two photoejected electrons leaving the others behind. Theoretical calculations describing these events from first principles will be applied to targets with many electrons that continue to interact with the fully correlated electrons before, during and after the photoionization event. It is hoped that this project can further elucidate the broader consequences of how all of the electrons bound to an atom or molecule can affect those that will be moved into the continuum and how consequences of symmetry and electronic structure impacts outgoing electrons. Both time-dependent and time-independent approaches will be explored. The work is closely coupled to kinematically complete experimental investigations of these systems.