© 2003 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim Coherent control of carrier population and spin in (111)-GaAs

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 ~100 fs 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. © 2003 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim 1 Introduction A number of schemes have been implemented that use optical fields to coherently control electron populations in semiconductors. Many of these schemes used one photon absorption of multiple phase-related optical pulses having a single frequency (i.e. a single color) [1–3]. Additionally, circularly polarized light can be used to generate spin-polarized carrier populations in direct-gap semi-conductors [4], and in the burgeoning field of “spintronics”, optics has played a key role in the injectio