Observation of dipole-dipole interaction in a degenerate quantum gas
  We have investigated the expansion of a Bose-Einstein condensate (BEC) of strongly magnetic chromium atoms. The long-range and anisotropic magnetic dipole-dipole interaction leads to an anisotropic deformation of the expanding Cr-BEC which depends on the orientation of the atomic dipole moments. Our measurements are consistent with the theory of dipolar quantum gases and show that a Cr-BEC is an excellent model system to study dipolar interactions in such gases. 
J. Stuhler, A. Griesmaier, T. Koch, M. Fattori, and T. Pfau, S.   Giovanazzi, P. Pedri and L. Santos