Plasmon excitation in MLG-GaAs heterostructure - Analytical expressions in long-wavelength limit

Abstract

Plasmon excitation plays important roles in many-body systems’ properties such as screening and drag in layer structures and is applied in plasmonic and photonic technology. This research is to consider the analytical expressions of plasmon frequencies in a double layer system made of mono–layer graphene (MLG) and GaAs quantum well with separation of and nonhomogeneous dielectric background at zero temperature. In this research, random–phase–approximation (RPA) is used to calculate the dielectric function of the system and to determine the plasmon modes by finding out zeroes of the function. Results represent that the zeroes of dielectric function admit two solutions (as in the case of semiconductor double quantum well systems or double-layer graphene – DLG), corresponding for optical (OP) and acoustic (AC) branch, respectively. Meanwhile the frequency of the former is proportional to root square of wave vector and depends on the dielectric constant of the surrounding layers, the frequency of the later is proportional to wave vector and depends on dielectric constant of contacting media and quantum well in long wavelength limit.

Keywords

• dielectric function
• plasmon excitation
• random – phase – approximation