Oct 18, 2012
High intensity spin currents
Contact : Laurent Vila

Figure: (a) Scanning Electron Microscope (SEM) image of the realized lateral spin valve structure with wires of 50 nm width. (b) Representation of non-local and local spin-valves measurements modes. (c) Representation of the different steps of the multiple angle evaporation technique.

Spintronics is an emerging field of research bridging magnetism and electronics. The spins of the electrical carriers are used to carry, store and process electrical information. This information technology paradigm relies on the control of spin currents, ie different flow of spin up and spin down. Amidst the large variety of proposed and developed spin structures, Lateral Spin Valves (LSV) devices are very interesting. They typically consist in two ferromagnetic electrodes connected by a non-magnetic material. The magnetic states of the electrodes allow tuning the electronic transport properties. Thanks to the numerous connections, they allow realizing non-local transport measurements by separating the spin current from the charge current.

 

This provides an efficient way to measure fundamental spin dependent transport properties in various materials, from metals and semiconductors to carbon allotropes and superconductors. In particular, LSV allows characterizing spin diffusion, spin-dependent tunneling at interfaces, spin absorption and spin transfer torque, as well as the spin Hall and Rashba effects...

 

The quality of a LSV can be quantified by its spin signal, which is the difference of non-local impedances between the antiparallel and parallel magnetization states of the electrodes. The spin signal depends mainly on the geometry of the LSV, on the quality of the interfaces, and on the choice of the used materials. We have optimized these parameters to obtain large spin signals in metallic systems. To obtain clean interface between the materials we developed a fabrication process, using different evaporation angles, to build in vaccum in a single step the LSV nanostructure shown in the figure.

 

Last update : 07/22 2014 (1049)

 

Retour en haut