Scanning Probe Microscopy for fundamental studies in nanoscience

原子力显微镜（AFM）是纳米科学的理想工具，因为它可以对单个纳米大小的物体进行成像、操作和表征。我的研究计划的长期目标是通过建立在最近NSERC DG资助的实验突破和仪器发展的基础上，继续获得关于信息存储或处理的纳米级系统的结构-性质关系的基本理解。该研究项目为HQP培训和许多潜在的社会经济技术衍生品提供了丰富、跨学科和世界级的环境。****我们正计划了解单分子器件的电导和机械性能，这些器件可以使用我们的两个独特的特高压原子力显微镜系统构成未来纳米电子学的基础。我们想要了解分子电子学中的问题：接触的作用。将现有的实验数据与理论模型进行比较是非常困难的，因为接触引线的原子结构非常重要，但通常无法通过实验控制。****一个进一步的项目是了解有机分子系统中的顺序和缺陷如何决定电导率和光电特性。通过用~ 100fs的光脉冲泵送样品，我们将产生激子并最终产生自由电荷。通过检测AFM尖端产生的静电力，我们将实现纳米尺度的空间分辨率。通过与光学和太赫兹光谱学专家的合作，我们将深入了解有机系统中的光-物质相互作用、电荷分离和电导率。****我们计划使用我们的低温原子力显微镜来表征半导体和金属量子点（QD）的充电。我们对机械检测到的单电子信号的详细定量理解使我们能够提取能级，状态密度以及单个和耦合量子点的耦合强度。我们将测试一个令人兴奋的理论预测，相干时间T1可以直接从我们的AFM耗散测量中提取！我们还旨在观察由于单个分子耦合到量子点而导致的电荷转移，从而导致实验可观察到的能级和能级排列的移动。通过改变耦合化学，这将导致对有机接触的详细理解。***最后，我们将继续努力从根本上理解生物系统如何处理信息。我们特别感兴趣的是了解是什么决定了神经元的信号处理能力。我们最近证明，我们可以构建新的、功能性的神经元连接。因此，我们现在可以通过实验控制所有相关参数来理解一个简单的生物神经网络，并将经验教训应用于工程纳米电子系统

The atomic force microscope (AFM) is an ideal tool for Nanoscience, as it allows imaging, manipulation and characterization of individual nanometer sized objects. The long-term aim of my research program is to continue to gain a fundamental understanding of the structure-property relation of nanoscale systems with respect to information storage or processing by building on recent NSERC DG funded experimental breakthroughs and instrumentation developments. This research program provides a rich, interdisciplinary and world-class environment for the training of HQP and many potential socio-economic technology spin-offs.****We are planning on understanding the conductance and the mechanical properties of single molecular devices that could form the basis of future nanoelectronics using our two unique UHV AFM systems. We want to understand THE issue in molecular electronics: the role of contacts. The comparison of currently available experimental data with theoretical modeling is very difficult, as the atomic structure of the contact leads is of utmost importance, but usually not experimentally controlled. ****A further project is to understand how order and defects in organic molecular systems determines conductivity and opto-electronic properties. By pumping the sample with ~100 fs optical pulses we will generate excitons and ultimately free charges. By detecting the resulting electrostatic forces on the AFM tip we will achieve nm scale spatial resolution. In collaboration with specialists in optical and THz spectroscopy we will thus gain a deep understanding of light-matter interactions, charge separation and conductivity in organic systems.****We plan to use our cryogenic AFM to characterize the charging of semi-conducting and metallic quantum dots (QD). Our detailed quantitative understanding of the mechanically detected single electron signals allows us to extract the energy levels, density of states as well as coupling strengths of individual and coupled QD. We will test an exciting theoretical prediction that the coherence time T1 can be directly extracted from our AFM dissipation measurement! We also aim to observe the charge transfer due to a single molecule coupled to a QD, resulting in a shift of the experimentally observable energy levels and energy level alignment. By changing the coupling chemistry this will lead to a detailed understanding of organic contacts. ***Finally, we will continue our efforts to fundamentally understand how biological systems process information. We are in particular interested in understanding what determines the signal processing capabilities in neurons. We recently demonstrated that we could construct new, functioning neuronal connections. We can thus now experimentally control all the relevant parameters to understand a simple biological neuronal network with a view of implementing the lessons learned in engineered nanoelectronics systems.**