Nonequilibrium dynamics and spin segregation in trapped gases

We consider harmonically trapped spin-1/2 gases quenched far from equilibrium by a Ramsey pulse. A magnetic field gradient is applied to the trapped gas, resulting in different trapping potentials for the two spin species. We model the dynamics using an effective spin model Hamiltonian with long range interactions, and use the spin model to understand the results of several experiments on spin diffusion and spin segregation in trapped gases.