Nonuniversal shot noise in quasiequilibrium spin valves
| Autor: | Kirill Nagaev, Tero Heikkilä |
|---|---|
| Rok vydání: | 2013 |
| Předmět: |
Physics
Fano factor Condensed Matter - Mesoscale and Nanoscale Physics Condensed matter physics Scattering Shot noise FOS: Physical sciences 02 engineering and technology Condensed Matter::Mesoscopic Systems and Quantum Hall Effect 021001 nanoscience & nanotechnology Condensed Matter Physics Polarization (waves) 01 natural sciences 3. Good health Electronic Optical and Magnetic Materials Condensed Matter::Materials Science Mesoscale and Nanoscale Physics (cond-mat.mes-hall) 0103 physical sciences Average current 010306 general physics 0210 nano-technology |
| Zdroj: | Physical Review B |
| ISSN: | 1550-235X 1098-0121 |
| Popis: | We show that the breakdown of the Wiedemann-Franz law due to electron--electron scattering in diffusive spin valves may result in a strong suppression of the Fano factor that describes the ratio between shot noise and average current. In the parallel configuration of magnetizations, we find the universal value $\sqrt{3}/4$ in the absence of a normal-metal spacer layer, but including the spacer leads to a non-monotonous suppression of this value before reaching back to the universal value for large spacer lengths. On the other hand, in the case of an antiparallel configuration with a negligibly small spacer, the Fano factor is $\sqrt{3 (1-P^2)}/4$, where $P$ denotes the polarization of the conductivities. For $P\rightarrow \pm 1$, the current through the system is almost noiseless. 5+ pages, 5 figures, including a short appendix |
| Databáze: | OpenAIRE |
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