Collective intersubband excitations in p-doped GaAs-AlGaAs multiple quantum wells

Abstract

We report on Raman spectroscopic investigations of collective spin-density (SDW) and charge-density waves (CDW) in the two-dimensional hole gas of a p-modulation doped GaAs/AlxGa1-xAs multiple quantum-well (MQW) structure and on the consequence of Landau damping of these excitations.
From the existence of collective SDW with energies lower than the border of the single-particle continuum we derive that exchange and correlation effects are of considerable strength in such hole gases.