Vertical shift register using dipolar interaction in magnetic multilayers

Chin, S.-L., Fernandez-Pacheco, A. , Petit, D. C.M.C. and Cowburn, R. P. (2015) Vertical shift register using dipolar interaction in magnetic multilayers. Journal of Applied Physics, 118, 233905. (doi: 10.1063/1.4937915)

Full text not currently available from Enlighten.


A vertical shift register consisting of multi-layered ferromagnetic bars with in-plane magnetization is investigated numerically using macrospin simulations. These layers are anti-ferromagnetically coupled via dipolar interactions and their in-plane aspect ratio determines their anisotropy. A single data bit is represented by a magnetic kink soliton, which forms at the boundary of two anti-parallel domains with opposite phases. It can be propagated bi-directionally using an externally applied rotating magnetic field. The soliton propagation is dependent on the applied field strength, the magnetic anisotropy of the ferromagnetic layers, and the dipolar coupling energies. For the device investigated here, the largest field range for soliton propagation is found to be from 35 Oe to 235 Oe at a lateral aspect ratio of 1.33. The soliton is also subjected to edge effects where it can be either pinned or reflected rather than being expelled from the stack. It is found that by reducing the thickness of the edge layer, these effects can be reduced substantially. By reducing the thickness of the edge layer by 20%, the field range in which the soliton is expelled increases by more than a factor of two.

Item Type:Articles
Additional Information:This project has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under Grant Agreement No. 309589 (M3d), as well as the Seventh Framework Programme ERC Contract No. 247368 (3SPIN). A.F.P. acknowledges funding from an EPSRC Early Career Fellowship, EP/M008517/1 and from the Winton Foundation.
Glasgow Author(s) Enlighten ID:Fernandez-Pacheco, Dr Amalio
Authors: Chin, S.-L., Fernandez-Pacheco, A., Petit, D. C.M.C., and Cowburn, R. P.
College/School:College of Science and Engineering > School of Physics and Astronomy
Journal Name:Journal of Applied Physics
Publisher:American Institute of Physics
ISSN (Online):0021-8979

University Staff: Request a correction | Enlighten Editors: Update this record