Atomic Physics Seminar: Stephen Eckel, “Cold-atom Circuits: Exploring Superfluid Transport”

Event time: 
Tuesday, February 16, 2016 - 10:00am to 11:00am
Sloane Physics Laboratory (SPL), 51 See map
217 Prospect St.
New Haven, CT 06511
(Location is wheelchair accessible)
Event description: 

Superfluidity, or flow without resistance, is a macroscopic quantum effect that is present in a multitude of systems, including liquid helium, superconductors, and ultra-cold atomic gases. I will present our work studying superfluid flow in a Bose-Einstein condensate (BEC) of sodium atoms. By manipulating optical potentials, we are able to form BECs into any shape, including rings and targets. Ring condensates are unique in that they can support quantized, persistent currents. We drive transitions between persistent current states using a rotating perturbation, or weak link. Both the strength of the perturbation and the temperature of the condensate affect the locations of these transitions, which can exhibit ferromagnetic-like hysteresis in certain regimes. The combination of the ring and rotating perturbation form a circuit that is analogous to an rf superconducting quantum interference device (SQIUD). These experiments shed new light onto the details of quantum transport and superfluidity and may pave the way for new ‘atomtronic’ devices.