Reducing the critical switching current in nanoscale spin valves
  The current induced magnetization reversal in nanoscale spin valves is a potential alternative to magnetic field switching in magnetic memory devices. We show that the critical switching current can be decreased by an order of magnitude by strategically distributing the resistances in the magnetically active region of the spin valve. In addition, we simulate full switching curves and predict a new precessional state. 
Jan Manschot, Arne Brataas, Gerrit E. W. Bauer