Spin-orbitronics, a new direction for spintronics
Prof. Dr. Albert Fert, Nobelpreis für Physik 2007 (Unité Mixte de Physique CNRS-Thales, Palaiseau and Université Paris-Sud, France)
Classical spintronic devices use the exchange interaction between conduction electron spins and local spins in magnetic materials to create spin-polarized currents or to manipulate nanomagnets by spin transfer from spin-polarized currents. A novel direction of spintronics – that can be called spin-orbitronics - exploits the Spin-Orbit Coupling (SOC) in nonmagnetic materials instead of the exchange interaction in magnetic materials to generate, detect or exploit spin-polarized currents. This opens the way to spin devices made of only nonmagnetic materials and operated without magnetic fields. Spin-orbit coupling can also be used to create new types of topological magnetic objects as the magnetic skyrmions or the Dzyaloshinskii-Moriya domain walls.
After a general and simple introduction on spintronics, I will review recent advances in two directions of spin-orbitronics:
a. Nucleation, current-induced motion and pinning of individual skyrmions or trains of skyrmions in films or multilayers: I will focus on skyrmions induced by Dzyaloshinsky-Moriya Interactions (DMI) at interfaces of ferromagnetic layers with materials of large spin-orbit coupling and I will discuss their potential for applications. It will include calculations of DMI, micromagnetic simulations ans preliminary experimental results on multilayers.
b. Conversion between charge and spin current by SOC (Spin Hall Effect and Edelstein Effect): I will describe recent experiments and applications to the current-induced motion of magnetic domain walls and the switching of nanomagnets.