title: Optical orientation of Mn2+ ions in GaAs in weak longitudinal magnetic fields.
abstract: We report on optical orientation of Mn2+ ions in bulk GaAs subject to weak longitudinal magnetic fields (B≤100  mT). A manganese spin polarization of 25% is directly evaluated by using spin-flip Raman scattering. The dynamical Mn2+ polarization occurs due to the s-d exchange interaction with optically oriented conduction band electrons. Time-resolved photoluminescence reveals a nontrivial electron spin dynamics, where the oriented Mn2+ ions tend to stabilize the electron spins.
authors.affiliation: Experimentelle Physik 2, Technische Universität Dortmund, 44221 Dortmund, Germany.
authors.forename: I A
authors.initials: IA
authors.lastname: Akimov
authors.forename: R I
authors.initials: RI
authors.lastname: Dzhioev
authors.forename: V L
authors.initials: VL
authors.lastname: Korenev
authors.forename: Yu G
authors.initials: YG
authors.lastname: Kusrayev
authors.forename: V F
authors.initials: VF
authors.lastname: Sapega
authors.forename: D R
authors.initials: DR
authors.lastname: Yakovlev
authors.forename: M
authors.initials: M
authors.lastname: Bayer