Optical spatio-temporal optical control of electron-induced processes at graphene-supported metal cluster nano-structures

石墨烯支撑金属簇纳米结构电子诱导过程的光学时空光学控制

• 批准号: 138792705
• 负责人: Professor Dr. Thorsten M. Bernhardt
• 金额: --
• 依托单位: Institut für Oberflächenchemie und Katalyse
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2009
• 资助国家: 德国
• 起止时间: 2008-12-31 至 2011-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/138792705?language=en
• 关键词: Optical; spatio; temporal; optical; control

In this proposal we wish to explore the potential of optimal control with shaped ultrafast laser pulses to localize the electromagnetic field in metal nano-cluster arrays consisting of graphene-supported size-selected silver clusters with extensions from a few atoms to the nanometer scale. Nothing is known so far about the optical properties of such arrays and we expect to find interesting new phenomena in particular also because of the intriguing electronic propensities of the 2D-material graphene. Graphene is employed as a substrate to provide a geometric template, i.e., to define the cluster distances – its potential to also provide electronic coupling between the clusters will be a subject of investigation. Size-selected clusters will be employed to obtain perfectly monodisperse samples and to investigate the effect of the transition from discrete to plasmonic electronic cluster structure on the possibility of field localization. Optical excitation will be provided by modulated (frequency, phase, polarization) ultrafast laser pulses. In a new experimental approach, the effect of the electromagnetic field localization will be probed by detecting the effectiveness of the electron-emission-induced dissociation of physisorbed adsorbate molecules (CH3Br, CH3Cl) on the metal clusters. Thus, the molecular fragment (CH3) mass signal will be employed as feedback signal in the control loop to obtain the optimal electromagnetic field. The investigation of the field localization will be performed by scanning tunnelling microscopic detection of the spatial extent of the metal cluster halogenation as a function of the parameters cluster size and cluster separation.

在本提案中，我们希望探索利用成形超快激光脉冲进行最佳控制的潜力，以将电磁场定位在由石墨烯支撑的尺寸选定的银簇组成的金属纳米簇阵列中，其范围从几个原子到纳米尺度。到目前为止，我们已经了解了此类阵列的光学特性，并且我们期望发现有趣的新现象，特别是因为二维材料石墨烯被用作基板以提供有趣的电子倾向。几何模板，即定义簇距离 - 它在簇之间提供电子耦合的潜力将成为研究的主题，将采用尺寸选择的簇来获得完美的单分散样品并研究从离散过渡的影响。在一种新的实验方法中，将通过调制（频率、相位、偏振）超快激光脉冲来提供光激励，以研究等离子体电子簇结构对场定位的影响。通过检测金属簇上物理吸附的吸附分子（CH3Br、CH3Cl）的电子发射诱导解离的有效性来探测，因此，分子碎片（CH3）质量信号将被用作控制回路中的反馈信号以获得。最佳电磁场的研究将通过扫描隧道显微镜检测金属簇卤化的空间范围作为簇尺寸和簇间隔参数的函数来进行。