Spinor condensate of 87Rb as a dipolar gas

We consider a spinor condensate of Rb-87 atoms in the F = 1 hyperfine state confined in an optical dipole trap. Putting initially all atoms in the m(F) = 0 component, we find that the system evolves toward a state of thermal equilibrium with kinetic energy equally distributed among all magnetic components. We show that this process is dominated by the dipolar interaction of magnetic spins rather than spin-mixing contact potential. Our results show that because of a dynamical separation of magnetic components, the spin-mixing dynamics in the Rb-87 condensate is governed by the dipolar interaction which plays no role in a single-component rubidium system in a magnetic trap.