Electronic excitations in microstructured MOS - systems

We have investigated the DC- and dynamic electronic properties of MOS-systems with spatially modulated charge density. The charge density modulation is induced via oxide modulation in lateral and cross-grating structures with typical periodicities of 500 nm. Magneto-conductance measurements are performed to characterize the charge density modulation. In spectroscopic investigations we find, that the charge density modulation strongly affects the collective excitation spectrum of the 2D-electron gas and induces minigaps in the 2D-plasmon dispersion.