Electron-hole scattering in a highly excited semiconductor quantum well amplifier with terahertz-field-drifted carrier distributions: applications toall-optical switching

Anisotropic carrier-carrier scattering is theoretically investigated for hi gh-density field-drifted electron-hole plasma distributions in semiconducto r quantum wells. The drifted distributions, driven for example by a free-el ectron laser, are found to march microscopically and rapidly back to an iso tropic, non-drifted plasma at the center of the Brillouin zone. This is in contrast to the single-species plasma case (p- or n-doped). We demonstrate that the presence of holes provides an efficient transport channel for elec tron relaxation and vice versa. Applications to all-optical switching and t erahertz-optical control of direct-gap semiconductors are discussed. (C) 20 00 Elsevier Science Ltd. All rights reserved.