Overcoming the Limits of Vortex Formation in Magnetic Nanodots by Coupling to Antidot Matrix

Magnetic vortices, the simplest topologically nontrivial magnetization configurations, have potential for applications in magnetic recording and microwave and spintronic devices. In the most studied case of an isolated magnetic dot, the vortex state can be achieved only in a relatively large dot. The authors show that dipolar coupling of a dot to a surrounding perpendicularly magnetized antidot supports vortices at reduced diameters and thicknesses, allowing enhanced efficiency and operating frequency, and even additional functionality, in vortex-based spintronic devices.