Jan 12, 2010

Current-driven spin torque induced by the Rashba effect in a ferromagnetic metal layer

Mihai Miron and Pietro Gambardella, member and leader of the Atomic Manipulation and Spectroscopy group at CIN2 (ICN-CSIC), together with other researchers from Grenoble, France, published 'Current-driven spin torque induced by the Rashba effect in a ferromagnetic metal layer' on Nature Materials.

Methods to manipulate the magnetization of ferromagnets by means of local electric fields^{1, 2, 3} or current-induced spin transfer torque^{4, 5, 6} allow the design of integrated spintronic devices with reduced dimensions and energy consumption compared with conventional magnetic field actuation^{7, 8}. An alternative way to induce a spin torque using an electric current has been proposed based on intrinsic spin-orbit magnetic fields^{9, 10} and recently realized in a strained low-temperature ferromagnetic semiconductor¹¹. Here we demonstrate that strong magnetic fields can be induced in ferromagnetic metal films lacking structure inversion symmetry through the Rashba effect. Owing to the combination of spin-orbit and exchange interactions, we show that an electric current flowing in the plane of a Co layer with asymmetric Pt and AlO_x interfaces produces an effective transverse magnetic field of 1 T per 10⁸ A cm^-2. Besides its fundamental significance, the high efficiency of this process makes it a realistic candidate for room-temperature spintronic applications.

PRESS REFERENCES:

ABC, ADN, Las Provincias, Ideal de Granada, Canarias 7, Heraldo de Soria, Nanotecnológica, Glogal Talent

+ PRESS RELEASE + Doi:10.1038/nmat2613