title: Transport and lifetime enhancement of photoexcited spins in GaAs by surface acoustic waves.
abstract: We demonstrate spin transport and spin lifetime enhancement in GaAs quantum wells induced by the traveling piezoelectric field of a surface acoustic wave (SAW). Spin transport lengths of about 3 microm corresponding to spin relaxation times during transport over 1 ns are observed, which are considerably longer than the exciton spin diffusion lengths in the absence of a SAW. The slow spin relaxation is attributed to a reduced electron-hole exchange interaction, when the carriers are spatially separated by the lateral potential modulation induced by the SAW.
authors.affiliation: Paul-Drude-Institut für Festkörperelektronik, Hausvogteiplatz 5-7, 10117 Berlin, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Sogawa
authors.forename: P V
authors.initials: PV
authors.lastname: Santos
authors.forename: S K
authors.initials: SK
authors.lastname: Zhang
authors.forename: S
authors.initials: S
authors.lastname: Eshlaghi
authors.forename: A D
authors.initials: AD
authors.lastname: Wieck
authors.forename: K H
authors.initials: KH
authors.lastname: Ploog