Effect of Valence-Band Mixing on Density Oscillations in 2D Hole Systems

We have calculated the spatial profile of density modulations generated in two-dimensional (2D) hole gases in response to an impurity potential. Both short-range and Coulombic point impurities are considered. The density response of hole systems turns out to be generally different from that seen in conduction-electron systems. Our results point to the importance of valence-band-mixing effects, especially in the regime of higher hole sheet densities.