CAREER: Precision Spectroscopy of milliKelvin Trapped Molecular Ions

Northwestern University, Evanston IL

Investigators

Abstract

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). This CAREER award supports an experimental research program to develop new techniques for high-precision measurements on cold trapped molecular ions. Sympathetic cooling of charged molecules to sub-Kelvin temperatures has recently been demonstrated, opening the way for orders of magnitude improvement in the accuracy available to molecular spectroscopy. However, the fledgling field of cold molecular-ion spectroscopy still awaits several technical developments, including preparation of trapped molecules in well-defined excited internal states and development of Doppler-free techniques commonly used for trapped atoms but not yet for molecules. These techniques will be developed and used to watch for gradual changes of molecular energy levels over the course of several years, thereby searching for time-variation of the electron-proton mass ratio. Surprisingly, this "constant" of nature is predicted to vary in time by many theories attempting to combine quantum mechanics with gravity, and discovery of such a time-variation would revolutionize our understanding of the universe. The broader impacts of this work result from leveraging both the laboratory research and local resources for effective education and outreach. An interactive Grades 4-6 Science Saturdays program will be developed in cooperation with the principal of Tarkington School of Excellence, the first Green-certified school in Illinois, located in the predominately Latino Marquette Park neighborhood of Chicago. The program will focus on the science of energy, using Materials World Modules developed at Northwestern University, resources from ANSER (Argonne Northwestern Solar Energy Research), and concepts from the experimental research program supported by this award.