Recent developments in the manipulation of magnetic domain walls in CoFeB-MgO wires for applications to high-density nonvolatile memories

The recent discovery that magnetic domain walls can be moved under a small current without any magnetic field opens a perspective for a paradigm shift in mass storage design. However, several fundamental questions must be answered before the technology can be considered feasible. This review covers the current understanding of domain wall (DW) propagation in CoFeB-MgO structures with perpendicular magnetic anisotropy. These films exhibit a very low density of pinning centers and can be integrated in Magnetic Tunnel Junctions, making them very promising for manipulating multiple domain walls in ultra-high-density spintronic devices. Several important issues are addressed: the physics of magnetic field, current and electric field driven domain wall motion, the characterization of the pinning potential on the nanoscale, the demonstration of artificial storing pinning sites, and the evaluation of domain wall propagation for logic and memory design integrated into complementary metal-oxide semiconductor (CMOS) technology.