This grant supports the development of an instrument to produce dense, cold, gases of potassium atoms in highly excited quantum mechanical orbits (Rydberg states). The atomic gases will have temperatures less than a thousandth of a degree above absolute zero. In highly excited states the electrons are very far from the nucleus, and are highly susceptible to interactions with external electric fields and other atoms.
Because of their remarkable properties, highly-excited atoms have the potential to provide insights into the dynamics of an array of quantum mechanical systems. The simple properties of highly excited potassium atoms will allow experiments that elucidate fundamental quantum processes of interest in chemical quantum control and in quantum information science. The strong, long-range, and non-isotropic nature of the interactions between atoms and measurements of the dynamics of many-atom systems is connected to ongoing experiments in condensed matter physics that employ ultracold samples of atoms and molecules.
The experiments that will be enabled by the instrument will address two overriding questions. The first question is how simple quantum systems behave when driven by strong fields. The second question is how energy transfer between atoms and molecules can be assisted or frustrated by light while in the presence of complex many-body interactions. The unique instrument will allow transformative research at a small college through experiments that complement research done in other atomic and molecular species at other institutions worldwide.
Developing the instrument involves design and construction of three distinct components to be added to a working system that produces cold ground-state atoms. The main goals of the development project are the following: (1) stabilizing lasers for excitation of the potassium electrons; (2) developing and constructing a structure to apply controlled electric fields to the atoms; and (3) developing and constructing a detector that can determine the energy levels of the individual atoms in the apparatus. Specifically, the following components will be added to the PI's existing potassium magneto optical trap (MOT): (1) stabilized ultraviolet and infrared lasers for stepwise excitation of ultracold potassium atoms from the ground-state to Rydberg states via the intermediate 5p level; (2) a radiofrequency transmission line to apply fields to the atoms that are compatible with the ultra-high-vacuum MOT; and (3) a state-selective field-ionization detector that does not perturb the Rydberg states.
The project involves extensive student training. The project will impact the education of many undergraduate students at Colby College both through their direct participation in instrument development and in classes affected by the project. The PI has been effective at integrating undergraduate students of all levels into his research program. Undergraduates working on the development of the instrument will receive training in state-of-the-art atomic physics and expertise in lasers, electronics, optical instrumentation, vacuum and radiofrequency technology, and computerized data acquisition and control systems.
