Spinor condensates in toroidal traps

Using magnetic traps, BECs are only prepared in particular magnetic internal states for which the Zeeman interaction produces a trapping geometry.  However, using optical traps, which are insenstive to the magnetic internal state, one can trap BECs in any internal state, allowing the spin of the atoms to be essentially a free parameter. Spinor condensates, which are multi-component condensates can be created in optical traps, where all magnetic sublevels of an internal state are populated. For our system, which starts in the F=1,mF=-1 state state, a spinor condensate would be populated in the F=1, mF=-1,0,+1. This allows another free parameter to be explored, and the populations of these states can be altered through spin-exchange collisions.

We have recently implemented RF and microwave antennas in our system. By proper application of these fields, we can prepare the condensate in mixtures or superpositions of various internal states through spin flips. This project will quantify and develop the methods, such as Rapid Adiabatic Passage to couple and prepare desired internal state mixtures. This will then be applied this to a condesates in our optically trapped ring geometry, and study the dynamics and superfluid behaviour of spinor condensates in these systems.