Monday, February 21, 2005

Dr. Lincoln Carr

JILA, University of Colorado, Boulder

"Achieving a Superfluid Pairing Transition in an Atomic Fermi Gas"

2:00 pm in room P-149

Abstract:  A rich system in which to explore quantum many body physics is that of cold trapped atomic gases. After overviewing some of these possibilities, I will discuss the Bardeen-Cooper-Schrieffer (BCS) to Bose-Einstein condensate crossover. Recently, experimentalists have created a new kind of Bose-Einstein condensate composed of bosonic molecules made of two fermionic atoms. A uniform external magnetic field can be changed adiabatically, thereby allowing one to dissociate the molecules into their constituent atoms. As I will show, the entropic advantage derived by the change from bosonic to fermionic statistics allows one to achieve the necessary temperature for a BCS Cooper-pairing-type phase transition. In addition to a BCS transition, this technique has led to the creation of new state of strongly interacting ultracold quantum matter.