Magnetic Skyrmions for Logic- and Memory Devices

Magnetic Skyrmions are nanoscale magnetic quasi-particles, most commonly imagined as rigid magnetic Bubbles. These can exist amongst others in thin films of magnetic materials with interfaces that contribute an antisymmetric exchange coupling.

As scaling of classical CMOS transistors is about to reach its physical limits and probably even sooner the limits of cost effectiveness, there is intense beyond CMOS research. One option to counteract this problematic is to (partially) replace CMOS logic by Beyond CMOS devices. One auspicious candidate herefore are magnetic logic devices due to their non volatility, inherent pipelining and low power operation.

Skyrmion logic devices are envisioned to implement fast in-memory logic operations in a high-density storage system by interaction of the Skyrmion “bits”. Using Skyrmions for devices and applications is the main goal of the “SPP2137 - Skyrmionics” DFG Priority Programme. We utilize our home-made sputter tool to engineer multilayer films, that are able to host such spin textures. For additional control, the magnetic properties can be locally modified by focused ion beam irradiation. We use this technique to create Skyrmion nucleation centers and envision it for Skyrmion tracks and devices.

To analyze the achieved changes, we employ various techniques. Laser magneto optical Kerr effect (MOKE) and anomalous Hall effect measurements can be used to get insight into coercive fields and effective anisotropy. These quantitative measurements are complemented by qualitative magnetic domain analysis, realized by widefield MOKE metrology and for deep sub-micron resolution magnetic force microscopy (i.e. AFM with a magnetic tip).

As an overarching goal, using these techniques, we want to build a proof-of-principle version of a Skyrmion logic gate.