Characterisation of the charge density modulation in periodic MOS structures by plasmon spectroscopy

In electron inversion layers on (100) Si MOS structures with laterally periodic oxide modulation plasmons are investigated with far-infrared transmission experiments. In such structures an applied gate voltage causes a static inversion charge density modulation which in turn gives rise to mini-gaps in the plasmon dispersion relation. The authors investigate the lowest mini-gap at plasmon wavevectors near the zone boundary of the first mini-zone induced by the periodic charge density modulation. The experimental results are compared with perturbation theory.