On the Dynamical Stability of the Hovering Magnetic Top
  In this paper we analyze the dynamic stability of the hovering magnetic top from first principles without using any preliminary assumptions. We write down the equations of motion for all six degrees of freedom and solve them analytically around the equilibrium solution. Using this solution we then find conditions which the height of the hovering top above the base, its total mass, and its spinning speed have to satisfy for stable hovering. The calculation presented in this paper can be used as a guide to the analysis and synthesis of magnetic traps for neutral particles. 
Shahar Gov (1), Shmuel Shtrikman (1 and 2) and Harry Thomas (3) ((1)   Weizmann Institute of Science, Rehovot, Israel (2) Un...