MTJs with a composite free layer for high-speed spin transfer torque RAM: Micromagnetic simulations

We demonstrate a substantial decrease of the switching time in penta-layer MTJs with a composite free layer regardless of the size and aspect ratio of the MTJ. The composite magnetic layer consists of two half-ellipses separated by a non-magnetic spacer. We analyze the peculiarities of the magnetic dynamics of these MTJs and reveal the physical reason for the decrease of the switching time. The scaling potential based on an analysis of the thermal stability is discussed. Furthermore, we outline the method for increasing the thermal.