RUI: Strong-Field Control of Intramolecular Dynamics in Polyatomic Molecules

Atoms can absorb energy from light, a process that excites their electrons. When molecules, which are composed of multiple atoms, absorb light in a similar manner, the energy can quickly be transferred away from the electrons and cause the atoms within the molecule to move. The atoms in the molecule can rotate about each other, they can vibrate by bending or stretching, or some collection of these events can occur, such as the unfolding of a ring of atoms. These sorts of behaviors are key steps in processes such as vision and photosynthesis. Understanding how this energy transfer is accomplished can help design more efficient collection of light or construct light-activated molecular switches. At an extreme level, intense, ultrashort laser pulses can manipulate molecular structure directly. In other words, the precise application of a specific laser pulse can act like a light-based reagent to steer a chemical process to a desired outcome. This basic research promotes progress in science by exploring how the excitation of electrons in molecules by light leads to changes in molecular structure and seeks ways of controlling those processes. These studies are done with undergraduate students, which provides motivation for further scientific education and leads to the development of a highly skilled workforce. These projects use sophisticated momentum imaging schemes to measure the structural evolution of molecules following the application of intense, ultrafast laser pulses. As part of these studies, we will continue to develop tools and techniques for collection and analysis of coincidence momentum imaging data, some of which might leverage machine learning or artificial intelligence. Rapid data collection and analysis can then be linked to ultrafast laser pulse shaping and used to explore coherent control of molecular dynamics, either through open- or closed-loop control schemes. Photoelectron circular dichroism is a sensitive probe of chiral molecular structure and one project aims to use these signals to probe laser-induced transitions from achiral to chiral structures. Collectively, these efforts explore fundamental questions about electronic to nuclear coupling in molecules and how these processes might be controlled. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria. NSF Award ID: 2607920 | Program: 01002627DB NSF RESEARCH & RELATED ACTIVIT | Principal Investigator: Eric Wells | Institution: Augustana University Association, SIOUX FALLS, SD | Award Amount: $230,573 View on NSF Award Search: https://www.nsf.gov/awardsearch/show-award/?AWD_ID=2607920 View on Research.gov: https://www.research.gov/awardapi-service/v1/awards/2607920.html