Ultrafast dynamic control of spin and charge density oscillations in a GaAs quantum well.
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.
Bao
J M
JM
Focus Center and Department of Physics, The University of Michigan, Ann Arbor, Michigan 48109-1120, USA.
Pfeiffer
L N
LN
West
K W
KW
Merlin
R
R