Lamine, Driss (2007) Effect of spin filter junctions in the ferromagnetic metal / semiconductor transport and interface effects. PhD thesis PMC, PMC, EP/X p.194.
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Alternative Locations: http://www.imprimerie.polytechnique.fr/Theses/Files/Lamine.pdf
Abstract
Spin dependent transport of hot electrons injected from vacuum into hybrid ferromagnetic layer/interface/semiconductor structures is studied. This original configuration allows one to study the spin polarized electron transport over a wide range of energies while still controlling their polarization.
Using ferromagnetic junctions Fe/oxide/GaAs designed in the laboratory, four operating regimes in the energy range 10 eV-3000 eV are observed. When increasing the injection energy, the gain of the transistor increases by 6 orders of magnitude, reaching value as high as 300 at 3000 eV, while the spin dependent transmitted current increases by 5 orders of magnitude reaching a maximum value around 1500 eV. The latter corresponds to 30 % of the incident current for a 100 % polarized electron beam. The four transport regimes are analyzed using an original quantitative model that takes into account both the multiplication which occurs in the metallic base and in the semiconductor by impact ionization, and the transmission coefficient at the interface between the base and the collector. In particular, the model reproduces experimentally observed threshold energies, above which the transmission efficiency increases steeply. By changing experimentally the injection energy it !
is possible to increase the hot electron distribution width at the base/collector interface until 10eV and thus to probe the interface profile. These results and their interpretations pave the way for future research in the field of spintronics, and especially in the design of a novel solid-state spin valve transistor device that could combine high spin selectivity with high gain and low operating noise.
| Item Type: | PhD Thesis (PhD) |
|---|---|
| Thesis Supervisor: | Lassailly, Yves |
| Date: | 26 October 2007 |
| Board of examiners: | Nguyen Van Dau, Fréderic and Peretti, Jacques and Weber, Wolfgang and Schuhl, Alain and Beauvillain, Pierre |
| Ecole Doctorale: | ED 447 ECOLE DOCTORALE DE L'ECOLE POLYTECHNIQUE |
| Discipline: | PMC |
| Collection (Fonds): | EP/X |
| Institution: | EP/X |
| Department: | PMC |
| Subjects: | 3. Physics, Optics |
| Uncontrolled Keywords: | Spintronics, Hot electrons, Spin filter effect, ferromagnetic Schottky diode, Transmission of hot electrons, Inelastic mean free path, Impact multiplication, électronique de spin, électrons chauds, Effet de filtre à spin, Jonctions métal ferromagnétique, Semi-conducteur, Transmission d'électrons polarisés, Libre parcours moyen inélastique, Multiplication par impact |
Table of content
Chapitre I : Préambule (page 1)
Chapitre II : Concepts généraux autour de l'électronique de spin (page 5)
Chapitre III : Réalisation et caractérisations d'un filtre à spin métal ferromagnétique / semi-conducteur (page 37)
Chapitre IV : Réalisation d'un transistor à vanne de spin sous ultra-vide : régimes de fonctionnement et performances (page 65)
Chapitre V : Modélisation du transport d'électrons chauds polarisés de spin dans les structures métal/semi-conducteur (page 109)
Chapitre VI : Conclusion et perspectives (page 153)
Bibliographie (page 157)
Annexe 1 : Article (page 165)
| ID Code: | 3479 |
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| Deposited By: | Laurence Vidament |
| Deposited On: | 28 February 2008 |
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