Materials Research Department, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt, Germany.
ACS Nano. 2012 Nov 27;6(11):9711-7. doi: 10.1021/nn303149p. Epub 2012 Oct 4.
We report on the experimental and the theoretical investigation of multipole surface plasmon resonances in metal nanowires conductively connected by small junctions. The influence of a conductive junction on the resonance energies of nanowire dimers was simulated using the finite element method based software CST Microwave Studio and experimentally measured by electron energy-loss spectroscopy in a transmission electron microscope. We extend the analysis of conductively connected structures to higher order multipole modes up to third order, including dark modes. Our results reveal that an increase in junction size does not shift significantly the antibonding modes, but causes a strong blue shift of the bonding modes, leading to an energetic rearrangement of the modes compared to those of a capacitively coupled dimer with similar dimensions.
我们报告了通过小连接点导电连接的金属纳米线中多极表面等离激元共振的实验和理论研究。使用基于有限元方法的 CST 微波工作室软件对导电连接对纳米线二聚体共振能的影响进行了模拟，并通过电子能量损失光谱在透射电子显微镜中进行了实验测量。我们将连接结构的分析扩展到更高阶的多极模式，包括暗模式，直到三阶。我们的结果表明，连接点尺寸的增加不会显著改变反键模式，但会导致键合模式的强烈蓝移，与具有类似尺寸的电容耦合二聚体相比，导致模式的能量重新排列。
