Abstract

We calculate collective excitations and damping rate in a double layer structure consisting of one monolayer gapped graphene sheet and a GaAs quantum well isolating two-dimensional electron gas within random-phase approximation at zero temperature. We observed that both in-phase optical and out-of-phase acoustic plasmon mode exist and can be un-damped in the system. The acoustic curve merges to single-particle excitation area boundary and disappear while the OP one crosses this border and continues in the region. Our analytical calculations present that the quantum well width has significant contribution only to acoustic mode in long wavelength limit. On the other hand, numerical results demonstrate that while both quantum well width and exchange–correlation effects decrease AC plasmon frequency, the OP one decreases with the increase in the band gap. Finally, taking into account local-field-correction in calculations leads to the decrease in only AC plasmon frequency, found mainly in large wave-vectors region.

Graphic Abstract

中文翻译：

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间隙石墨烯-GaAs双层系统中的交换相关效应和层厚度影响等离子体激元模式

摘要

我们计算了一个双层结构中的集体激发和阻尼率，该双层结构由一个单层带隙石墨烯片和一个GaAs量子阱组成，在零温度下以随机相近似的方式隔离二维电子气。我们观察到同相光学和异相声等离振子模式都存在，并且在系统中可以不衰减。声学曲线合并到单粒子激发区域边界，然后消失，而OP越过该边界并在该区域继续。我们的分析计算表明，在长波长范围内，量子阱宽度仅对声模有重大贡献。另一方面，数值结果表明，尽管量子阱宽度和交换相关效应都降低了交流等离子体激元频率，OP 1随带隙的增加而减小。最后，在计算中考虑局部场校正会导致交流等离子激元频率降低，而这种现象主要出现在大的波矢区域。

图形摘要