Since its inception, quantum mechanics has intrigued both scientists and non-scientists alike due to its prediction of mind-boggling phenomena that seem to defeat common sense. These include the tunnel effect (particles penetrating through walls), entanglement and non-locality (long-range spooky actions that seem incompatible with special relativity and causality), and quantum coherence of large objects. This project aims at harnessing quantum-mechanics rules to achieve objectives in the fields of molecular physics, the quantum dynamics of large particles (Rydberg atoms) in trapping structures, and high-precision spectroscopy to measure fundamental constants. Work in these areas furthers progress in fundamental and applied science, is important for continued national progress in technological infrastructure and defense, and is necessary to maintain competitiveness within the international landscape. Through student involvement, the project also contributes to the development of a capable scientific workforce, which is essential for a technology-driven economy.
The research is focused on quantum-dynamical studies of Rydberg atoms. These are atoms that have an electron in a highly excited state, leading to a rich internal electronic structure with many quantum-mechanical states. A quantum description of the atomic center-of-mass motion is added to arrive at a comprehensive quantum-mechanical description that includes both internal and external degrees of freedom, needed to accomplish new goals in both theoretical and experimental research. Methods of high-precision laser spectroscopy are employed to measure optical and sub-Terahertz atomic transitions, allowing one to determine atomic and ionic polarizabilities, as well as the Rydberg constant. This high-precision-measurement component of the work is important because it helps solving a challenge known as the "proton radius puzzle", which has recently arisen in advanced fundamental science. The center-of-mass motion of Rydberg atoms trapped in periodic, laser-generated wells (optical lattices) is manifest in vibrationally resolved lattice modulation spectra, in Bloch oscillations induced by electric-dipole forces acting onto the atoms, and in atom-interferometric effects (such as the Talbot effect). These aspects may lend themselves to future practical measurement and sensing applications. In Rydberg molecules, improved atom localization tools and time-resolved imaging of the Rydberg atoms on sub-atomic length scales enable direct studies of vibrational dynamics. This component is important because it advances the understanding of novel classes of molecules that involve paradigms of molecular binding that were, until recently, unknown. The work is accompanied by studies on optical circularization of Rydberg atoms, the continued development of multi-photon electromagnetically-induced transparency as an all-optical readout of spectroscopic data, and the pursuit of ultra-clean optical-lattice potentials using optical cavities.
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.
