Download or read book Direct Evidence for LO Phonon Reabsorption by Free Holes in Gallium Arsenide Quantum Wells written by Peter Brockman and published by . This book was released on 1995 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The influence of an electron-hole plasma with a temperature close to that of the ambient lattice on the population lifetime of non-equilibrium LO phonons created by the relaxation of hot carriers is studied in a GaAs quantum well sample that was designed to allow one to clearly separate LO phonon emission from absorption processes. For the experiments a novel multiple-beam Raman scattering technique was developed that allows one to separately control the LO phonon generation and the electron-hole plasma injection process. The lifetime of non-equilibrium, small wavevector LO phonons is found to decrease from 4.5ps to 1.9 ps as the density of the plasma is increased to ~3.1011 cm-2 by adjusting the intensity of an infrared laser tuned close to the lowest subband gap of the quantum well. This result represents the first direct experimental evidence from the lattice perspective for longitudinal optical (LO) phonon reabsorption by free carriers.