Abstract: A topological spin memory effect, defined as the recovery of magnetic skyrmions or magnetic bubble skyrmions in magnetic thin films after a transition to a dramatically different spin texture, is used for encrypted non-volatile information storage. The storage strategy is based on magnetic skyrmions, that is, topologically protected spin textures comprising chiral domain walls surrounding small (e.g., nanometers to microns in diameter), typically circular, single-domain cores. Systems and methods are described for encrypted non-volatile information storage based on a spin memory effect in magnetic thin films that support skyrmions. Systems and methods encrypt and recover information stored in the form of magnetic skyrmions.

Abstract: The determination of the strength of an in-plane magnetic field utilizing one or more magnetically-soft, ferromagnetic member, having a shape, size and material whereas a single magnetic vortex is formed at remanence in each ferromagnetic member. The preferred shape is a thin circle, or dot. Multiple ferromagnetic members can also be stacked on-top of each other and separated by a non-magnetic spacer. The resulting sensor is hysteresis free. The sensor's sensitivity, and magnetic saturation characteristics may be easily tuned by simply altering the material, size, shape, or a combination thereof to match the desired sensitivity and saturation characteristics. The sensor is self-resetting at remanence and therefore does not require any pinning techniques.