基于含时密度泛函理论，研究了随着间距改变时硅烯量子点二聚物的等离激元激发特性。沿垂直于硅烯所在平面方向激发时，在一定间距范围内，硅烯量子点二聚物中形成了长程电荷转移激发模式。参与长程电荷转移激发的π电子主要在两个量子点之间运动。该等离激元模式随着间隙的减小发生蓝移。此外，在不同间距时，体系中还有两个等离激元共振带，分别位于7和15 eV附近。沿平行于硅烯所在平面方向激发时，由于两个量子点之间的耦合，在低能
The properties of plasmon excitations in silicene quantum dot dimers are investigated using timedependent density functional theory.Within a certain gap distance,a long-range charge transfer plasmon mode appears in silicene quantum dot dimers due to an impulse excitation polarized in the direction perpendicular to the quantum dot plane.The π electrons that participate in this plasmon excitation mostly move between the two quantum dots.This plasmon mode is blue-shifted as the gap distance decreases.Moreover,for different gap distances,two main plasmon bands appear,one around 7 eV and the other around 15 eV.In the low-energy region of the spectrum,for an impulse excitation polarized in the direction parallel to the silicene quantum dot plane,the shape of the absorption spectrum and the corresponding peak intensity of the silicene quantum dot dimers are both equivalent to those of a single silicene quantum dot,due to coupling between the two dots