Fundamental Research Division
The DRF at the CEA assemble approximately 6,000 scientists since January 2016.
Scientific result | Spintronics | New technologies
In an ordinary planar waveguide, such as the one the scientists have modeled, spin waves travel indifferently in both directions.
Opting for a guide formed by a stack [(nickel-iron) alloy – platinum] on silicon permits the use of a specific interaction present at the alloy-platinum interface. This Dzyaloshinskii-Moriya interaction has the effect of shifting the frequency spectra of the waves propagating along the two opposite directions. Cleverly selecting the spatial excitation frequency then makes it possible to select only one way of propagation, while "turning off" the other.
This can be achieved by producing the spin wave by means of a second metallic guide that is perpendicular to the first and whose comb-like shape makes it possible to select the wave excitation vector, and consequently, the spin wave spatial period.
Spin waves could increase the efficiency of logical architectures (which currently rely upon CMOS devices) by allowing an undulatory logic at nanometric scale. They can, in fact, transfer information that is encoded in its amplitude and/or its phase. Additionally, their nanometric wavelength at frequencies in the gigahertz-terahertz range, as well as their integrability on a chip and their compatibility with non-volatile magnetic memories, makes them particularly competitive (compared to photonics, for instance).
Creation of unidirectional spin-wave emitters by utilizing interfacial Dzyaloshinskii-Moriya interaction, Physical Review B
CEA is a French government-funded technological research organisation in four main areas: low-carbon energies, defense and security, information technologies and health technologies. A prominent player in the European Research Area, it is involved in setting up collaborative projects with many partners around the world.