Effects of power fluctuation on fast magnetic field detection using a spin-torque oscillator

We study the effects of power fluctuation on a high-data-transfer-rate read head with a spin-torque oscillator using a nonlinear oscillator model. By numerically solving the model under random sequences of applied pulsed magnetic fields (corresponding to stray fields from data bits), the bit-error rate is estimated. For a large damping rate of power, the bit errors are caused primarily by phase fluctuation that is enhanced by amplitude-phase coupling. In contrast, for a small damping rate of power, the bit errors are caused primarily by power fluctuation and are independent of amplitude-phase coupling.