Magnetoplasmons in modulated two-dimensional electronic systems

By using an analytically derived dynamical density response function of a unidirectional periodically modulated two-dimensional electron gas under a perpendicular magnetic field, we study the magnetoplasmon modes in this system within the random-phase approximation. It is found that the modulation potential does not introduce an additional low frequency mode nor cause high frequency magnetic oscillations in the principal magnetoplasmon mode, as has been previously reported. However, there exists a shift in the principal mode due to the modulation, and this shift is a slow oscillatory function of the inverse magnetic field.