This project will develop a set of quantum theories for a systematic understanding of fundamental atomic and molecular processes over a wide range of temperatures, from zero kelvin, where everything behaves quantum mechanically, to room temperature, where certain aspects of the atomic and molecular motion have evolved into classical behavior, but with subtle quantum effects remain that can play a crucial role in astronomy, chemistry, condensed matter, and biology. While quantum theories can be relatively simple near absolute zero temperature, it can become exceedingly difficult at higher temperatures where the number of states has grown dramatically. Can we efficiently deal with quantum systems with many states? Can quantum theories for atoms and molecules be not only accurate, but also sufficiently simple and systematic that they can be used to build new quantum theories for more complex few-body and many-body systems? These are the fundamental questions that we expect to make progress on, based upon a set of conceptual and mathematical advances that the PI, his students, and colleagues have accumulated in over a decade.
In terms of broader impact, atomic and molecular interactions and processes are at the very foundation of physical sciences. There is a wide range of applications in areas ranging from cold atoms to astrophysics. This work will allow substantially new, accurate yet simple quantum theories for atomic and molecular processes to be developed. This project will involve the training of graduate students. These students will be well trained in fundamental quantum physics of atoms and molecules. This will allow them to develop new theories and models in other areas of physical sciences such as astronomy, chemistry, condensed matter, and biology.
