ABSTRACT
This chapter provides an updated overview of the physics and engineering behind magnetic domain wall racetrack memory (RTM). Whether bits of data are coded using magnetic domains or domain walls (DWs), data manipulation in the RTM is based on the motion of DWs along the racetracks. There are two main classes of materials suitable for RTM. The first class comprises materials with small intrinsic anisotropy, which are usually referred to as magnetically “soft” materials. The second class of materials has a very large anisotropy, which is perpendicular to the plane of the wafer. The fundamental difference between in-plane magnetic anisotropy and perpendicular magnetic anisotropy materials leads to different scaling properties. Scaling considerations differ also greatly for horizontal or vertical RTM designs. The chapter discusses the case of horizontal RTM, which is more challenging in terms of storage density. The most promising readout method for RTM relies on a local tunnel magnetoresistance measurement.
