Dynamic band-structure modulation of quantum wells by surface acoustic waves

The dynamical modulation of the band structure of GaAs quantum wells by a surface acoustic wave (SAW) is investigated using photoluminescence (PL) spectroscopy. The strain field of the SAW modulates the excitonic transitions, leading to a splitting and to a polarization anisotropy of the excitonic PL lines. The oscillator strength of the split line gives direct information about the spatial distribution of carriers in the potential modulation induced by the SAW.