[PAST EVENT] Andrew Rotunno, Physics - Final Oral Dissertation Defense [Zoom]

June 21, 2021
12pm - 3pm
Drew Rotunno

Andrew Rotunno , Physics - Final Oral Dissertation Defense

Zoom link is available upon request. Please email [[w|evwilk,Ellie]]

Title: Radiofrequency AC Zeeman Trapping for Neutral Atoms

Abstract: This thesis presents the first experimental demonstration of a two-wire AC Zeeman trap on an atom chip. The AC Zeeman energy is a resonant, bipolar, state-dependent atomic energy shift produced by alternating magnetic fields with frequencies near hyperfine transitions. We demonstrate that high gradients in this energy, as near an atom chip, can produce a spin-state selective force greater than gravity for ultracold rubidium atoms. Our novel AC Zeeman trap is generated by a local minimum in AC Zeeman energy. This trap has trap frequency on the order of a few hundred Hz, trap depth about 5 ?K, and quarter-second lifetimes for less than one Watt of RF power. This proof of principle work enables new types of experiments, especially our motivating focus, spin-dependent trapped atom interferometry, in more complex geometries. Different parameters in the current arrangement can produce regions of linear gradient, flat saddle points, square and donut shaped traps, offering a new set of tools to ion and atom chip experimenters. This thesis also presents the relevant dressed atomic theory, four AC Zeeman trap designs, Rabi frequency measurement, numerical trap simulations, and the AC skin effect in wide rectangular wires.

Bio: Drew Rotunno was born in 1992 in Syracuse, NY, and lived in the suburb Liverpool for 20 years. His first job was delivering newspapers, before spending 5 years employed as a maintenance worker at a church. He attended grade school within walking distance, and later drove across town to attend Christian Brothers Academy, where an exceptional science department fostered his interest and abilities in the sciences. He went to Fordham University in The Bronx, NY, where he served as president of the Fordham Experimental Theatre club, and took extra classes in philosophy. His physics pursuits during college include digital holography in Dr. Stephen Holler's lab at Fordham, and developing an ion neutralizing system under Dr. Itzik Ben-Itzhak at Kansas State. He went on to become a graduate student at William & Mary, making some of Seth Aubin's ideas come to life, adding some of his own, and fabricating a number of personal projects in the Small Hall Makerspace. Pending this defense, he will go on to research Rydberg atoms as calibrated RF sensors as a postdoc researcher in Chris Holloway's lab at NIST in Boulder. He is a proud keeper of three rabbits and enjoys British game shows.