Coherent control of carrier population and spin in (111)-GaAs

We report independent coherent control of carrier population and spin in (111)-oriented GaAs arising through quantum interference of the transition amplitudes associated with one- and two-photon absorption of similar to100 A phase-locked optical pulses. We demonstrate this coherent control using various combinations of pulse polarizations and crystal orientations. In addition, we present a phenomenological framework for the spin and population control, and present predictions based on a macroscopic symmetry analysis that agree with our experimental observations.