Spin injection, detection and manipulation in nanoscale devices

OTKA CNK 80911

Principal investigator:  Dr. MIHÁLY György

Duration: 36 months (2010.07.01 – 2013.06.30)

Financial support: 137 536 000 Ft

The use of the electron spin for information processing is the central concept of spintronics. In macroscopic circuits the spin information is lost due to different scattering mechanisms. However, a spin polarized current injected to a nonmagnetic conductor keeps the spin memory within 10 - 1000 nm. The detection of spin polarization at nanoscale, together with the possibility of the manipulation of nanomagnets, opens the route for novel sensor, memory and even logic applications.

In this project we investigate the spin injection, detection and manipulation in various fabricated nanostructures. The systems to be investigated include metallic layers, semiconductor nanowires, carbon based nanostructures (graphen, nanotubes), atomic size nanojuntions (single atoms, gold and carbon atomic chains).

The nanoscaled circuits will be prepared by electron lithography and characterized by magnetotransport experiments. Bulk properties of the components will be determined separately: the magnetism of the ferromagnetic contact layer by magneto-optical Kerr effect, the spin lifetime by ESR, the spin diffusion length by Andreev spectroscopy, etc. The atomic size nanojunctions will be characterized by transmission probabilities (noise measurements, subgap spectroscopy).

The research will be carried out on devices containing single domain nanomagnets or even clusters of a few magnetic atoms. Based on the above novel materials we build up structures suitable for spin-dependent electronics. We also investigate how spin injection with high current density reverse the magnetization of a magnetic cluster. We intend to produce a nanoswitch based on this novel phenomenon, but also investigate spin-independent solutions, e.g. voltage controlled switching in metallic junctions and/or in atomic chains.

The experimental and theoretical expertise brought together in the project offers a good chance to develop nanoscale devices with potential spintronic applications.