In the next step, Christian Pfleiderer and his team made further measurements at the MIRA instrument of the neutron source FRM II in an attempt to determine why the lattice twisted when a current was applied. At first, the calculations of the theoreticians contradicted the results of the experiments in Garching. "The magnetic structure twists, because the direction of the electric current is deflected extremely efficiently by quantum mechanical effects," explains Christian Pfleiderer. When an electron flies through the magnetic vortex, the electron's spin reacts to the vortex (see animation). In this way the electric current exerts a force on the magnetic vortices, which eventually begin to flow.
After further measurements, the team of Christian Pfleiderer and Achim Rosch was able to establish that the newly discovered lattice of magnetic vortices displays properties that have been of interest in nanotechnology for quite some time. They are, among other things, relevant to the development of new data storage systems. Notably, the magnetic vortices are very stable and at the same time very weakly anchored in the material, so that even the weakest of electric currents can lead to movement. This should allow data to be written and processed considerably faster and more efficiently in the future.
In this animated illustration, an electron (black ball) flies across a lattice of magnetic vortices. The forces transferred in the process allow the magnetic structures to be controlled with relatively small electric currents.
(Photo Credit: Copyright Prof. A. Rosch, Universitaet Koeln, and W. Schumann, TU Muenchen.)
This illustration shows how magnetic vortices in manganese silicon form a regular lattice.
(Photo Credit: Copyright Christian Pfleidere, TU Muenchen.)
Source: Technische Universitaet Muenchen