PGI-1 Seminar: Prof. Dr. Kirill Belashchenko
Spin injection from a half-metal at finite temperatures
- 02 Jul 2013 15:30
University of Lincoln, Nebraska, USA
Spin injection from a half-metallic electrode in the presence of thermal spin disorder is analyzed using a combination of random matrix theory, spin-diffusion theory, and explicit simulations for the tight-binding s-d model. Although the two-current model is inapplicable to half-metals, a generalization of the "conductivity mismatch" obstacle to spin injection shows that this is not restricted to electrodes described using this model.
It is shown that efficient spin injection from a half-metal is possible as long as the effective resistance of the normal metal does not exceed a characteristic value, which does not depend on the resistance of the half-metallic electrode but, rather, is controlled by spin-flip scattering at the interface. The general conclusions are confirmed by tight-binding s-d model calculations. A rough estimate suggests that efficient spin injection from true half-metallic ferromagnets into silicon or copper may be possible at room temperature across a transparent interface.
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