Friday 12 Oct 2012: Colloquium: How a little spin transfusion can help to build multi-functional magnetic nano-devices : from spin torque oscillators to multi-functional artificial synapses devices
Prof. Julie Grollier - Unite Mixte de Physique CNRS-Thales
Newman F 12:00-13:00
Discovered in 1996 , the spin transfer effect allows to manipulate the magnetization of nano-devices by transfusion of angular momentum from a spin polarized current. Due to the rich scale of possible applications, as well as the new physics at stake, the spin transfer effect has sparked off many fundamental and applicative studies. Thanks to recent advances on this topic, the next generation of magnetic random memories (STT-RAM), expected to be out on the market in less than three years, will use this phenomena to write the magnetization state encoding the '0' or '1'.
During this talk, after a brief introduction on the physical origin of the spin transfer effect, I will focus on our recent research on more fundamental aspects of spin transfer induced dynamics. The first part will be devoted to our progress towards implementing powerful, frequency agile spin transfer nano-oscillators with high spectral purity. I will describe in particular one of the routes we are following to improve the dynamic properties of our devices : the synchronization of several of these non-linear oscillators. In the last part, I will show how the spin transfer effect can also be used to engineer artificial synapses for neuromorphic computing : spintronic memristors, through the fast (> 500 m/s) motion of a magnetic domain wall.
 J. C. Slonczewski, J. Magn. Magn. Mater. 159, 1 (1996) & L. Berger, Phys. Rev. B 54, 9353 (1996)