A periodic disturbance in local ferromagnetic ordering can propagate in a magnetic material in the form of a wave called a spin wave or a magnon. “Magnonics” is a field of research for the forthcoming beyond CMOS era; it harnesses magnons to transmit and process information using sophisticated spin wave devices and conduits. The standard spin wave conduits rely on spin waves in in-plane magnetized materials. There the spin waves are difficult to guide in curved conduits because of their anisotropic dispersion properties. Besides, miniaturization to deep sub-micron dimensions is a challenge as spin waves are sensitive to structural changes such as lithography-induced roughness at the conduit edges.
We proposed recently to develop novel conduits that would rely on the channeling of spin waves in the domain walls of perpendicularly magnetized films [F. Garcia-Sanchez et al., Phys. Rev. Lett. 114, 247206 (2015)]. In these materials, the symmetries ensure that spin waves can propagate along bends in the spin wave conduits. The size of the domain wall width can be fine-tuned below 50 nm with appropriate material choices, without the need to resort to lithography. In addition, the domain walls can be placed at the desired locations and thereby confer total reconfigurability of the spin wave routing circuitry. Finally, the domain wall spin waves have their frequencies in the spin wave gap of the surrounding film, which prevents radiation loss out of the conduit.
About the position
The candidate will nanofabricate spin wave devices based on this concept. The candidate will characterise these devices using mainly microwave low noise electrical measurements and will implement the modeling using both analytical techniques and numerical micromagnetics. The research will be carried out within a consortium funded by the French National Research Agency (ANR) with collaborators in Nancy and Strasbourg.
Contact and further information
Jean-Paul Adam (jean-paul.adam [at] u-psud.fr)