Selective field ionization (SFI) is used to determine the state or distribution of states to which a Rydberg atom is excited. By evolving a small perturbation to the ramped electric field using a genetic algorithm, the shape of the time-resolved ionization signal can be controlled. This allows for the separation of signals from pairs of states that would be indistinguishable with unperturbed SFI. Measurements and calculations are presented that demonstrate this technique and shed light on how the perturbation directs the pathway of the electron to ionization. Pseudocode for the genetic algorithm is provided. Using the improved resolution afforded by this technique, quantitative measurements of the 36p3/2 + 36p3/2 --> 36s1/2 + 37s1/2 dipole–dipole interaction are made.
Gregoric, Vincent C.; Bennett, Jason; Gualtieri, Bianca R.; Hastings, Hannah P.; Kannad, Ankitha; Liu, Zhimin Cheryl; Rabinowitz, Maia R.; Rowley, Zoe A.; Wang, Maio; Yoast, Lauren; Carroll, Thomas J.; and Noel, Michael W., "Perturbed Field Ionization for Improved State Selectivity" (2020). Physics and Astronomy Faculty Publications. 11.
The item available here for download is the accepted version of the article originally published in Journal of Physics B: Atomic, Molecular and Optical Physics, 53 (2020), 084003 (11 pp). Copyright 2020, IOP Publishing, Ltd.