Spin currents without electric currents
Alexey Kavokin (Physics and Astronomy School, University of Southampton, UK)

Infos Complémentaires

↦ Voir en ligne :
Enregistrement audiovisuel sur le site ENS - Savoirs en multimédia

Salle 236, 29 rue d’Ulm - 13h30

↦ Voir en ligne : Enregistrement audiovisuel sur le site ENS - Savoirs en multimédia

Jeudi 12 mars

Résumé : The spin Hall effect consists in the generation of a spin current
perpendicular to the charge current fl-ow. Thirty-fi-ve years after its prediction
by Dyakonov and Perel’ it is in the focus of experimental and theoretical
investigations and constitutes one of the most remarkable effects of spintronics.
Due to scattering and dephasing in electronic gases, it is diffi-cult to observe and
has only been evidenced for the fi-rst time a few years ago. Recently, my group
has predicted and the group of Alberto Bramati at Laboratoire Kastler Brossel
observed the optical spin Hall effect (OSHE) which consists in a separation in
real and momentum space of spin-polarized exciton-polaritons generated by a
laser in a semiconductor microcavity. These results show a high potential for
the excitonic spintronics, i.e. spintronics without electric currents. The long
lived coherence of exciton-polaritons and their unusual spin properties make
them excellent candidates for ultrafast delivery of quantum information over
macroscopic distances. In this talk I will address the mechanisms of generation
and control over exciton polariton spin currents in semiconductors and discuss
the perspectives for excitonic spintronics.