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M Alouani

Publications and source records attributed to M Alouani.

At least 19 recordsLinked to original sources
PubMed2006

Electron spin precession upon reflecting from ferromagnetic surfaces.

Electrons with the polarization vector perpendicular to the magnetization of Fe, Co, and Ni films are spin analyzed after reflecting from the ferromagnet. At low primary electron energies a strong spin motion is found, namely, a precession of the polarization around the magnetization and a change of the angle between the polarization and the magnetization. This observation can be accounted for by the existence of spin-dependent gaps in the electronic band structure of the ferromagnets.

Journal Article↗
PubMed2006

Huge excitonic effects in layered hexagonal boron nitride.

The all-electron GW approximation energy band gap of bulk hexagonal boron nitride is shown to be of indirect type. The resulting computed in-plane polarized optical spectrum, obtained by solving the Bethe-Salpeter equation for the electron-hole two-particle Green function, is in excellent agreement with experiment and has a strong anisotropy compared to out-of-plane polarized spectrum. A detailed analysis of the excitonic structures within the band gap shows that the low-lying excitons belong to the Frenkel class and are tightly confined within the layers. The calculated exciton binding energy is much larger than that obtained by Watanabe et al. [Nat. Mater. 3, 404 (2004).] based on a Wannier model assuming h-BN to be a direct-band-gap semiconductor.

Journal Article↗