3D Magnetic Vortices ObservedCategory: Science & Technology
Posted: May 9, 2013 07:16AM
Materials are magnetic when the electrons within them are aligned in a common direction, as each electron has its own magnetic field, and these add up to the larger field of the material. Electrons do not need to line up like that though for the material to have special magnetic properties. For the first time, researchers at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) have observed a new magnetic alignment that may have interesting applications for transmitting information wirelessly.
Magnetic vortices are created when a material's electrons align in a circular path, like mini bar magnets placed end-to-end in a circle, with those in the middle pointing straight up or down. If you connect this to a DC power source, the vertical electrons will start rotating in a circle and emitting electromagnetic waves. If the speed of the DC signal is too high, those electrons will flip upside down, which impairs the ability to use them to transmit data. What the HZDR researchers found was a way to create three-dimensional vortices, which should not have this problem, at least not until higher speeds, because the electrons near the core are nearly vertical and reinforce those at the center. This prevents the flipping.
The material the researchers created is comprised of two magnetic disks, roughly 10 nm thick and 500 nm wide, with a nonmagnetic disk separating them. Potentially this tiny device could be made into an antenna capable of transmitting in the gigahertz range, where Wi-Fi networks currently operate.