Micromagnetic simulations of a reconfigurable domain wall device

Abstract

The design of ultra-dense, low-cost and low-power technologies is one of the current challenges belonging to future Nanoscience and Nanotechnology breakthroughs. They represent advances which can qualitatively improve Information Technologies and strongly impact in the nowadays society. Among other important topics, the research on novel magnetic systems is a key factor to successfully accomplish these challenges. In this framework the present work moves in the direction of reconfigurable magnetic devices: systems where the response of the device can be controlled through an external agent. Based on the racetrack idea, a hybrid device is micromagnetically simulated to control the propagation of domain walls (DW) through the Magnetic Nanowire (MNW). Disc shaped structures of a material with weak Perpendicular Magnetic Anisotropy (PMA) are located at both sides of the MNW to control the DW propagation by means of magnetostatic fields. The key factor for the functionality of the proposed device is the difference between the coercive fields of both, the weak PMA elements and the magnetic pad (MNW), allowing the DW propagation by the application of biasing fields and or polarized currents, without changing the configuration of the discs. Depending on the magnetic state preconfigured in the discs, different magnetostatic fields are applied locally to the MNW leading to controllable pinning effects acting on the DW. The proposed device is sensitive to the chirality property of DWs leading to filtering/rectifying capabilities.