An investigation into switching probability in electric field-induced precessional magnetization switching

We report on a theoretical investigation into the switching probability of electric field-induced precessional magnetization switching, by solving the Fokker-Planck equation numerically with a finite difference method. The switching probability is determined by the net magnetic field induced by the deviation of the precession angle from its equilibrium position after the precession process. The error rate is at its lowest value under an appropriate applied external field for the voltage pulse duration tau(pulse) a little longer than the half-precession period. The calculated results show that an ultra-low error rate, down to the order of 10(-12), can be achieved for thermal stability factor Delta = 50, and that a low damping factor material should be used for the free layer to improve the switching probability. For the parallel (anti-parallel) magnetization to anti-parallel (parallel) magnetization switching process, the spin transfer torque tends to decrease (increase) the error rate when the tau(pulse) is shorter than the half-precession period, and increase (decrease) the error rate when tau(pulse) is longer than the half-precession period. These results exhibit the potential of electric field-induced precessional magnetization switching for application in ultra-low power, high speed magnetic random access memory.