THEORETICAL INVESTIGATIONS OF IONIZATION PROCESSES IN AN ULTRACOLD QUANTUM RYDBERG GAS
Abstract
The Rydberg atoms (RA) are large and easily manipulated by external probes. At low temperatures thermal motion of a gas of these molecules is very negligible, and the stability of the gases depends hence on many delicate atomic processes, not all of which are independent of each other. In particular, the ionization process leads eventually to cold plasmas. Some of the basic collision physics involved are complex, as the RA can be unstable even for a minute disturbance. Therefore, it is crucial to elucidate these non-thermal processes by analyzing the processes at the basic level, and then introducing systematically the complexity in a controlled way. We propose to carry out theoretical studies of the basic atomic/molecular processes which affect the stability and relaxation of an ultracold Rydberg gas, especially molecular autoionization (MAI), and the molecular collisional ionization (MCI) and electron RA collisions (eRC), all at very low energies. (I) The MAI will be treated fully quantum mechanically, starting with the Rydberg states of low principal quantum number n, and eventually extracting the accurate n and density dependence of the process. This is augmented by numerical study that can include complex atomic cores and their polarizations. Contribution of states near the ionization threshold will be carefully analyzed, as they seem to have the dominant effect. (II) Similarly, the MCI will be studied with special emphasis on the long-range interactions between two RA’s, and also between a RA and an ion at very low energies. The range of the interaction will be determined, which depends strongly on the degeneracy of the system. The dipole blockade is sensitive to such potential tails. (III) Finally, the eRC involving the free electrons produced by the MAI, e.g., will be analyzed using the continuum Hartree-Fock method, developed recently in this laboratory, but modified to suit the RA targets. The results of this project will guide the interpretation of available experimental data and direct new experiments, paving the way for possible exploitation of the properties of Rydberg gas in quantum computing and information control, two areas of interest to DoD and its mission. The research and educational activities described in the proposed project will have significant impacts on science and technology education, and diversity at Delaware State University (DSU), a historically black university with a large pool of talented students who have been traditionally underrepresented in STEM fields. This research proposal and the expected results will not only provide the firm theoretical foundation for the future research program, but also strengthen and enhance the visibility of the theoretical quantum computing program that the PI is striving to establish and to integrate with ongoing and growing activities in Atomic, Molecular, and Optical Sciences at DSU. The computer programs developed in this project can be essential in other related fields and give valuable training of students. This activity will be integrated with the undergraduate curriculums and DSU courses in AMO sciences. More significantly, DSU students will participate and be trained in diverse advanced areas of computational physics, atomic physics, and quantum computing, allowing them to be well-positioned for entering a demanding multidisciplinary job market / pursuing a terminal degree in STEM fields if they chose to. Enrollment and Retention of students in Physics will naturally increase because of our successful efforts.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Apr 20, 2023
- Source ID
- FA95502210416
Entities
People
- Essaid Zerrad
Organizations
- Air Force Office of Scientific Research
- Delaware State University
- United States Air Force