title: Ultrafast dynamic control of spin and charge density oscillations in a GaAs quantum well.
abstract: We use subpicosecond laser pulses to generate and monitor in real time collective oscillations of electrons in a modulation-doped GaAs quantum well. The observed frequencies match those of intersubband spin- and charge-density excitations. Light couples to coherent density fluctuations through resonant stimulated Raman scattering. Because the spin- and charge-related modes obey different selection rules and resonant behavior, the amplitudes of the corresponding oscillations can be independently controlled by using shaped pulses of the proper polarization.
authors.affiliation: Focus Center and Department of Physics, The University of Michigan, Ann Arbor, Michigan 48109-1120, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Bao
authors.forename: L N
authors.initials: LN
authors.lastname: Pfeiffer
authors.forename: K W
authors.initials: KW
authors.lastname: West
authors.forename: R
authors.initials: R
authors.lastname: Merlin