3D Nanomagnetic Logic

Abstract

Digital computation by magnetic ordering? That sounds useless or crazy having powerful CMOS technologies available everywhere at low cost. However, if it comes to massively parallel and pipelined digital operations with stringent power constraints, 3D Nanomagnetic Logic might pay off. This chapter gives an insight on an experimentally demonstrated complete set of logic devices, where the entities are not electrically connected but fully powered and operated by magnetic clocking fields. The computing elements are comprised of ferromagnetic islands of sub-micrometer size, whereas the binary “0” and “1” is encoded in magnetic northand south-pole. This is accomplished by ferromagnetic thin-film materials that show magnetic anisotropy perpendicular to the plane of the chip. The anisotropy is locally reduced by focused Ga+ ion radiation in order to program computation functionality into close-by magnetic islands. Digital signals are propagated by field-driven domain-walls in lateral direction and via field coupling in vertical direction, enabling monolithic 3D integration. Based on majority votes that can be re-programmed to the universal NAND or NOR function, a hybrid co-processor integrated in the backend-of-line CMOS technology is envisioned. Still far from being ready for mass fabrication, but containing all basic elements for 3D integrated computation with nonvolatile magnetic states .