A theoretical study on how synchronization and resonance-like phenomena insuperparamagnetic tunnel junctions can be driven by spin-transfer torques ispresented. We examine the magnetization of a superparamagnetic free layer thatreverses randomly between two well-defined orientations due to thermalfluctuations, acting as a stochastic oscillator. When subject to an external acforcing this system can present stochastic resonance and noise-enhancedsynchronization. We focus on the roles of the mutually perpendiculardamping-like and field-like torques, showing that the response of the system isvery different at low and high-frequencies. We also demonstrate that thefield-like torque can increase the efficiency of the current-driven forcing,specially at sub-threshold electric currents. These results can be useful forpossible low-power, more energy efficient, applications.
展开▼
