We report Raman measurements of the $k_{?}$ dependence and temperature dependence of the imaginary part of the dielectric function of the electron gas in modulation-doped GaAs/${\mathrm{Al}}_{\mathrm{x}}$${\mathrm{Ga}}_{1\mathrm{-}\mathrm{x}}$As quantum wells. The Raman spectra are well explained by the Lindhard response function, using a phenomenological single-particle relaxation time ${\tau }_{\mathrm{SP}}$. We determine the temperature dependence of ${\tau }_{\mathrm{SP}}$.

• Received 2 March 1987

DOI:https://doi.org/10.1103/PhysRevB.36.1565