激发
纳米棒
共振(粒子物理)
偶极子
物理
上部结构
激发态
等离子体子
离散偶极子近似
极化(电化学)
合并(版本控制)
分子物理学
材料科学
光学
纳米技术
化学
原子物理学
计算机科学
量子力学
热力学
物理化学
情报检索
作者
Xuxing Lu,Weixiang Ye,Wen-Long You,Hao Xie,Zhi Hong Hang,Yun Lai,Weihai Ni
出处
期刊:Physical review
日期:2020-01-30
卷期号:101 (4)
被引量:3
标识
DOI:10.1103/physrevb.101.045431
摘要
Chiroptical responses of helical superstructures are determined by collective behaviors of the individual building blocks. In this paper, we present a full theoretical description of the collective resonance in superstructures. We use the gold nanorods as individual building blocks and arrange them helically along an axis in an end-to-end fashion. Numerical simulations on single unit cells reveal that the plasmonic coupling between the nanorods produces hybridized resonances, whose intensity is strongly dependent on the excitation light with left- or right-handed circular polarizations (LCP or RCP). A node-mode criterion is proposed on the basis of the microscopic mechanism, which successfully explains the difference between LCP and RCP. We further demonstrate, by repeating the unit cell from 1 to infinity along the helical axis, the multiple hybridized resonances gradually evolve and merge into a single collective resonance, whose energy is also dependent on LCP and RCP. An analytical description is provided for the collective resonance of the helical superstructure on the basis of the coupled dipole approximation method. Our theory shows that $n$ collective resonance modes are present in the helical superstructure with the unit cell consisting of $n$ nanorods. Strikingly, only one resonance can be excited by the incident light with certain circular polarization. We propose a universal selection rule for such selective excitation of the collective resonances by analyzing the symmetry of the helical superstructures. The insights provided in this work may shed light on future designs and fabrications of helical superstructures using plasmonic building blocks.
科研通智能强力驱动
Strongly Powered by AbleSci AI