Synthetic exchange coupled composite for widening an in-plane ballistic switching region

This study proposes synthetic exchange coupled composites to control ballistic switching effectively. We performed macrospin simulations for the ballistic switching of in-plane magnetized nanomagnets with varying antiferromagnetic coupling constant. It was discovered that there exists an optimal value of the antiferromagnetic coupling constant at which the ballistic switching region can be widened to 3.3 times of that of the single hard nanomagnet, where the antiferromagnetic coupling field torque significantly counteracts the demagnetizing field torque of the hard nanomagnet. The ballistic switching region is also effectively widened due to the volume-averaging of saturation magnetizations; that is, the cancelation of demagnetizing fields at the large antiferromagnetic coupling beyond the optimal value.