Three-Dimensional Magnetic Page Memory

The increasing need to store large amounts of information with an ultradense, reliable, low-power, and low-cost memory device is driving aggressive efforts to improve on current perpendicular magnetic recording technology. However, the difficulties in fabricating small-grain recording media while main- taining thermal stability and a high signal-to-noise ratio motivate the development of alternative methods, such as the patterning of magnetic nanoislands and use of energy assistance for future applications. In addi- tion, from both a sensor perspective and a memory perspective, three-dimensional spintronic devices are highly desirable to overcome the restrictions on the functionality in planar structures. Here we demonstrate a three-dimensional magnetic memory (magnetic page memory) based on thermally assisted and stray- field-induced transfer of domains in a vertical stack of magnetic nanowires with perpendicular anisotropy. Use of spin-torque-induced domain multiplication in such a device with periodic pinning sites provides additional degrees of freedom by allowing lateral information flow to realize truly-three-dimensional integration.