运用含时密度泛函理论研究等边三角形钠原子团簇中的表面等离激元激发.发现:在团簇尺寸较大时,沿三角形底边和底边中垂线方向激发的共振模式不同,然而沿两方向的吸收光谱线形一样,主要吸收峰的共振能量也相同.低能聚集共振在空间引起电场增强的极大值主要分布在三角形的端点附近.
Plasmon excitation in small sodium clusters with triangle structure is studied with time-dependent density functional theory. For relatively larger sodium clusters, along triangle bottom edge and perpendicular bisector of triangle bottom edge, linear shapes of absorption spectra and resonance energies of main absorption peaks are same. However, along these directions, resonance modes of main absorption peaks are different. For the main plasmon mode, field enhancement extrema are located in region of endpoints of the triangle.