Communication Between Magnetic Tunnel Junctions Using Spin-Polarized Current for Logic Applications

We investigated spin-polarized current controlled magnetic tunnel junctions (MTJs) connected with a nano-magnetic channel using micromagnetic simulations. A spin polarized current is used to switch the MTJ and form a domain wall in the nanochannel that is captured at a notch in the channel. A current can then be applied along the nanochannel to drive the domain wall to the other MTJ. The nanochannel design was optimized by varying MTJ pillar size, nanochannel width, material, and notch sizes. Both in-plane and perpendicular anisotropy were simulated. Perpendicular anisotropy was found to be the most beneficial by alleviating the dominate effect of shape anisotropy. Four different nanochannels were connected to a single MTJ with perpendicular anisotropy and a domain wall formed in each channel. This allows fan out to be realized and consequently more complex logic functions. The current densities to switch the MTJ elements and drive the domain wall were found to be on the order of 1 × 10⁸ A/cm² and 6 × 109 A/cm², respectively.