Three-Dimensional Magnetic Recording: An Emerging Nanoelectronic Technology

An overview of three-dimensional magnetic recording as a next-generation nanoelectronic data storage technology is presented. It is proposed to stack magnetic bits in a third (vertical) dimension. Several implementations of a three-dimensional recording system are analyzed. A clear distinction between absolute three-dimensional recording and its trivial multilevel implementation is drawn. The main focus is on the study of write and read processes. One of the proposed mechanisms to access data during writing and reading is to control a relatively strong and adequately localized magnetic field using a patterned soft magnetic underlayer under the three-dimensional recording media. During the write process, the use of the underlayer allows increasing the recording field and simultaneously maintaining adequate high resolution across the entire thickness of the recording media. Similarly, according to the reciprocity principle, during the readback process, the "softness" of the underlayer strongly influences the sensitivity field and thus could be used as a mechanism to identify a unifield plane across the thickness. As an option, it is proposed to minimize the intersymbol interference and improve stability through patterning of the recording media in all three dimensions. The physics of three-dimensional magnetic recording is investigated via the nanoprecision spinstand measurements, magnetic force microscopy, and Landau-Lifshits-Gilbert-based micromagnetic modeling.