Collective excitations of a two-dimensional electron gas in a two-dimensional magnetic-field modulation

The magnetoplasmon spectrum of a weakly modulated two-dimensional electron gas system

The magnetoplasmon spectrum of a magnetically modulated two-dimensional electron gas (2DEG) is investigated. We derive the inter- and intra-Landau-band magnetoplasmon spectrum within the self-consistent field approach. The derivation is performed at zero temperature as well as at finite temperature. Results are presented for the inter- and intra-Landau-band magnetoplasmon spectrum as a function of the inverse magnetic field. Magnetic Weiss oscillations are found to occur in the magnetoplasmon spectrum as a result of magnetic modulation. Furthermore, our finite temperature theory facilitates the analysis of effects of temperature on the magnetoplasmon spectrum. The results are compared with those obtained for an electrically modulated 2DEG system. In addition, we derive and discuss the effects of simultaneous electric and magnetic modulations on the magnetoplasmon spectrum of the 2DEG when the modulations are in phase as well as when they are out of phase. Magnetic oscillations are affected by the relative phase of the two modulations and the position of the oscillations depends on the relative strength of the two modulations in the former case while we find complete suppression of Weiss oscillations for a particular relative strength of the modulations in the latter case.