Magnonics: concepts and applications

Spin waves (SW) are the collective oscillations in magnetic materials with their associated quantum of excitation called magnons (as phonons are to lattice vibrations). Magnons exhibit a rich dynamics including anisotropy, non-reciprocity, non-linear frequency shifts and magnon-magnon interactions in the form of “collisions” including scattering, splitting and confluence. Besides their fundamental interest when dealing with problems involving magnetization dynamics, the magnons are used for microwave signal processing (present) and are promising for unconventional computing applications.

In this seminar, I will introduce the semiclassical theory of spin waves, based on the linearized Landau-Lifshitz equation in order to give their dispersion relation and to understand of the phenomena underlying non-reciprocity. I will also review some of the non-linear processes and detail how they offer new avenues for microwave signal processing like passive frequency conversion, frequency-selective power limitation, spatio-temporal frequency demultiplexing and comb generation.

Thibaut Devolder, Jean-Paul Adam, Titiksha Srivastava, Alexandre Hamadeh, Claude Chappert and Joo-Von Kim.

Novel magnetic devices (NOMADE) team, Centre de nanosciences et de nanotechnologies