1. Very low critical current density for motion of coupled domain walls in synthetic ferrimagnet nanowires
- Author
-
Lepadatu, Serban, Saarikoski, Henri, Beacham, Robert, Benitez, Maria Jose, Moore, Thomas A., Burnell, Gavin, Sugimoto, Satoshi, Yesudas, Daniel, Wheeler, May C., Miguel, Jorge, Dhesi, Sarnjeet S., McGrouther, Damien, McVitie, Stephen, Tatara, Gen, and Marrows, Christopher H.
- Subjects
Condensed Matter - Mesoscale and Nanoscale Physics - Abstract
Domain walls in ferromagnetic nanowires are potential building-blocks of future technologies such as racetrack memories, in which data encoded in the domain walls are transported using spin-polarised currents. However, the development of energy-efficient devices has been hampered by the high current densities needed to initiate domain wall motion. We show here that a remarkable reduction in the critical current density can be achieved for in-plane magnetised coupled domain walls in CoFe/Ru/CoFe synthetic ferrimagnet tracks. The antiferromagnetic exchange coupling between the layers leads to simple N\'{e}el wall structures, imaged using photoemission electron and Lorentz transmission electron microscopy, with a width of only $\sim 100$~nm. The measured critical current density to set these walls in motion, detected using magnetotransport measurements, is $1.0 \times 10^{11}$~Am$^{-2}$, almost an order of magnitude lower than in a ferromagnetically coupled control sample. Theoretical modelling indicates that this is due to nonadiabatic driving of anisotropically coupled walls, a mechanism that can be used to design efficient domain-wall devices., Comment: Supplmentary Information as ancillary file
- Published
- 2016
- Full Text
- View/download PDF