[PAST EVENT] Tommy Allen Byrd: Physics Dissertation Defense

December 1, 2014
2pm - 4:30pm
Small Hall, Room 122
300 Ukrop Way
Williamsburg, VA 23185Map this location
Researchers have long been interested in electron transport through mesojunctions containing time-dependent potential energies, a process often called "quantum pumping" useful model of such a system is a ballistic atom pump, which consists of two reservoirs of neutral ultracold atoms connected by a channel containing oscillating repulsive potential-energy barriers. Under certain conditions, such pumps can create net transport of atoms from one reservoir to the other, and energy can be pumped out of or into each reservoir even when there is no net particle transport. These pumps are studied from classical and quantum-mechanical perspectives, and semiclassical theory is used to explain some scattering properties which are not easily explained by quantum theory. This system is also a nice model of chaotic transport. Escape-time plots showing the time for classical trajectories to escape the barrier region display a type of fractal self-similarity. A topological theory using a discrete map of the system in the phase plane is developed, and this theory predicts and explains the features seen in escape-time plots.

Tommy Allen Byrd was born and grew up in northeast Tennessee. After high school, he worked various jobs for a few years but eventually decided to go to college. He received a B.S. in physics from East Tennessee State University in 2008.

Tommy began graduate school at Clemson University in 2008 studying astrophysics, but he didn't like it, and he transferred to The College of William and Mary in 2009. There, he worked with advisor John Delos and collaborated with Seth Aubin. His work focused on the theory of atom pumping, and chaotic transport. He earned an M.S. in physics in 2011.