This paper aims to investigate collective excitations in a double-layer structure consisting of two parallel bilayer graphene sheets within random-phase-approximation. We determine the collective excitations in the system from the zeroes of the temperature-dependent dynamical dielectric function. Numerical results demonstrate that both optical in-phase and acoustic out-of-phase plasmon modes are found in the system, similar to other double-layer structures. Calculations prove that plasmon frequencies increase with the increase in temperature while the imbalance in doping density between two bilayer graphene sheets as well as the increase in carrier density decrease these frequencies. Similar to the case of zero temperature, increasing separation increases (decreases) acoustic (optical) plasmon frequency. Our computations illustrate that temperature affects remarkably and can reduce the effects of other factors on plasmon properties in double bilayer graphene systems.

本文旨在研究由随机相位近似内的两个平行双层石墨烯片组成的双层结构中的集体激发。我们从与温度相关的动态介电函数的零点确定系统中的集体激发。数值结果表明，在系统中发现了光学同相和声学异相等离子体模式，类似于其他双层结构。计算证明等离子体频率随着温度的升高而增加，而两个双层石墨烯片之间的掺杂密度不平衡以及载流子密度的增加降低了这些频率。与零温度的情况类似，增加分离会增加（减少）声（光）等离子体频率。