Levitation of Bose-Einstein condensates induced by macroscopic   non-adiabatic quantum tunneling
  We study the dynamics of two-component Bose-Einstein condensates trapped in different vertical positions in the presence of an oscillating magnetic field. It is shown here how tuning appropriately the oscillation frequency of the magnetic field leads to the levitation of the system against gravity. This phenomenon is a manifestation of a macroscopic non-adiabatic tunneling in a system with internal degrees of freedom. 
Katsuhiro Nakamura, Akihisa Kohi, Hisatsugu Yamasaki, Victor M.   Perez-Garcia