Magnonics is a research field in nanoscience exploring spin waves, i.e. magnons, to transmit and process information.
Magnons are elementary spin excitations in magnetic materials which exhibit a wave-like state. These can either be
localized or propagate through the solid.
(Left) Illustration of spin helices in a magnetic material that spontaneously forms the Skyrmion lattice phase controlled by external parameters such as temperature and magnetic field (Illustration: Christoph Hohmann, NIM, Germany). (Right) Breathing mode of the Skyrmion lattice phase (Animation by M. Garst and J. Waizner, Universitaet zu Koeln, Germany). [more information: click here]
The magnonic crystal, i.e., the magnetic counterpart of the photonic crystal, is a paradigm of magnonics. Ferromagnetic materials with periodically modulated properties offer an artificially tailored band structure for spin waves consisting of allowed frequency bands and forbidden frequency gaps. Thereby the full control of the flow of spin waves is achieved.
We follow two approaches: the 'bottom-up' approach where Skyrmions (a kind of magnetic vortex) form a periodic lattice in helimagnets with lattice constants of down to about 20 nm, and the 'top-down' approach where we nanopattern ferromagnetic thin films.
Before magnonics turns into applications, there is lots of fundamental physics to be explored. This site provides an overview of our research on spin waves at the nanoscale.
|Transmission through a
Permalloy antidot lattice, after pulsed spin excitation at the top. The
magnetic field of 100 mT is applied in horizontal direction. The
animation covers about 2 ns. For further details, see link "magnonic