Plasmon modes in BLG-GaAs Double-Layer Structures: Temperature Effects

We consider a double-layer structure consisting of a bilayer graphene sheet and a two-dimensional electron gas, isolated in a very thin GaAs quantum well. The collective excitations are determined from the zeroes of the dynamical dielectric function within the random-phase approximation, taking into account the temperature effects. Numerical calculations present that two plasmon modes exist in the system, similar to those in other double-layer structures. While the optical mode continues in the interband single-particle excitation area, the acoustic mode only crosses the intraband single-particle excitation boundary and disappears. Also, our investigations show that plasmon properties in the system are affected significantly by most of the chosen factors. Plasmon frequency increases as the separation increases while the increase in carrier density decreases noticeably these frequencies. Temperature affects plasmon characters similarly to but more weakly than that does in monolayer grapheme-two-dimensional electron gas double-layer structures. Finally, the temperature can increase the effects of some other parameters on plasmon properties of the system, so this factor should be taken into account in calculations to improve the model for better results.

Automated summary

The study investigates plasmon excitations in a double-layer structure, revealing the existence of two plasmon modes in the system. The optical mode continues in the interband single-particle excitation area, while the acoustic mode only crosses the intraband single-particle excitation boundary and disappears. Plasmon frequency is affected by separation and carrier density, with temperature having a weaker impact on plasmon properties compared to other factors.