Landau damped intersubband plasmons in InAs/AlSb quantum wells

We present a combined theoretical and Raman scattering study of coupled intersubband plasmon-LO phonon modes in InAs/AlSb quantum wells, highlighting the importance of the InAs conduction band nonparabolicity in such systems. We demonstrate that under the illumination conditions of the Raman measurements, electron densities can be as high as 4 x 10(exp12) cm(exp -2) and give evidence of Landau damping of intersubband plasmons.