title: Optical pumping of the electronic and nuclear spin of single charge-tunable quantum dots.
abstract: We present a comprehensive examination of optical pumping of spins in individual GaAs quantum dots as we change the net charge from positive to neutral to negative with a charge-tunable heterostructure. Negative photoluminescence polarization memory is enhanced by optical pumping of ground state electron spins, which we prove with the first measurements of the Hanle effect on an individual quantum dot. We use the Overhauser effect in a high longitudinal magnetic field to demonstrate efficient optical pumping of nuclear spins for all three charge states of the quantum dot.
authors.affiliation: Naval Research Laboratory, Washington, DC 20375, USA.
authors.forename: A S
authors.initials: AS
authors.lastname: Bracker
authors.forename: E A
authors.initials: EA
authors.lastname: Stinaff
authors.forename: D
authors.initials: D
authors.lastname: Gammon
authors.forename: M E
authors.initials: ME
authors.lastname: Ware
authors.forename: J G
authors.initials: JG
authors.lastname: Tischler
authors.forename: A
authors.initials: A
authors.lastname: Shabaev
authors.forename: Al L
authors.initials: AL
authors.lastname: Efros
authors.forename: D
authors.initials: D
authors.lastname: Park
authors.forename: D
authors.initials: D
authors.lastname: Gershoni
authors.forename: V L
authors.initials: VL
authors.lastname: Korenev
authors.forename: I A
authors.initials: IA
authors.lastname: Merkulov