title: Optical spin initialization and nondestructive measurement in a quantum dot molecule.
abstract: The spin of an electron in a self-assembled InAs/GaAs quantum dot molecule is optically prepared and measured through the trion triplet states. A longitudinal magnetic field is used to tune two of the trion states into resonance, forming a superposition state through asymmetric spin exchange. As a result, spin-flip Raman transitions can be used for optical spin initialization, while separate trion states enable cycling transitions for nondestructive measurement. With two-laser transmission spectroscopy we demonstrate both operations simultaneously, something not previously accomplished in a single quantum dot.
authors.affiliation: Naval Research Laboratory, 4555 Overlook Ave, SW, Washington DC 20375, USA.
authors.forename: Danny
authors.initials: D
authors.lastname: Kim
authors.forename: Sophia E
authors.initials: SE
authors.lastname: Economou
authors.forename: Stefan C
authors.initials: SC
authors.lastname: Bădescu
authors.forename: Michael
authors.initials: M
authors.lastname: Scheibner
authors.forename: Allan S
authors.initials: AS
authors.lastname: Bracker
authors.forename: Mark
authors.initials: M
authors.lastname: Bashkansky
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Reinecke
authors.forename: Daniel
authors.initials: D
authors.lastname: Gammon