Coupling of plasmon and dipolar modes in a monolayer of MoS2

摘要

The dielectric function of a monolayer of molybdenum disulfide is investigated within the model of two band metal using the random phase approximation (RPA). The large direct bandgap in a monolayer of MoS_2 leads to the appearance of the interband dipolar mode which couples to the intraband plasmon mode. This results in two hybridized modes. The renormalized dipolar mode is close to its bare value, while coupling suppresses the plasmon mode. The obtained modes are responsible for the appearance of dispersing peaks in the energy-loss function.