Macroscopic quantum coherence in spinor condensates confined in an   anisotropic potential
  We investigate the macroscopic quantum coherence of a spin-1 Rb condensate confined in an anisotropic potential. Under the single-mode approximation, we show that the system can be modeled as a biaxial quantum magnet due to the interplay between the magnetic dipole-dipole interaction and the anisotropic potential. By applying a magnetic field along the hard-axis, we show that the tunneling splitting oscillates as a function of the field strength. We also propose an experimental scheme to detect the oscillatory behavior of the tunneling splitting by employing the Landau-Zener tunneling. 
Yixiao Huang, Yunbo Zhang, Rong L\"u, Xiaoguang Wang, Su Yi
cond-mat.quant-gas