Spin-dependent photoelectron tunneling from GaAs into magnetic cobalt
Résumé
The spin dependence of the photoelectron tunnel current from free standing GaAs films into outof-plane magnetized Cobalt films is demonstrated. The measured spin asymmetry (A) resulting from a change in light helicity, reaches ±6% around zero applied tunnel bias and drops to ±2% at a bias of -1.6 V applied to the GaAs. This decrease is a result of the drop in the photoelectron spin polarization that results from a reduction in the GaAs surface recombination velocity. The sign of A changes with that of the Cobalt magnetization direction. In contrast, on a (nonmagnetic) Gold film A ≈ 0%.
Domaines
Matière Condensée [cond-mat]| Origine | Fichiers produits par l'(les) auteur(s) |
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