Vibrational spectroscopy with a scanning tunnelling microscope: The role of the tip

非弹性电子隧穿谱是一种重要的技术，它可以在原子尺度上研究振动或磁激发。振动光谱学为扫描隧道显微镜的能力增加了化学灵敏度，因此代表了一种重要的手段，例如，表面化学它进一步使磁激发的分析，如单原子自旋翻转。这种调查是至关重要的磁数据存储设备的发展在最终的大小。然而，非弹性电子隧穿的激发截面往往很弱。此外，在振动光谱中，在可能的振动模式的流形中，通常仅在光谱中观察到少数模式或甚至没有模式。选择规则已经发展到合理化这些意见的吸附物和基板的电子结构和振动模式的对称性。然而，尖端的作用几乎没有被讨论-无论是实验还是理论。本项目的主要目标是填补这一空白，系统地研究原型单原子和单分子的振动光谱与可控修改的提示。

Inelastic electron tunnelling spectroscopy is an important technique, which enables the investigation of vibrational or magnetic excitations at the atomic scale. Vibrational spectroscopy adds chemical sensitivity to the capabilities of a scanning tunnelling microscope and thus represents an important means in, e.g., surface chemistry. It further enables the analysis of magnetic excitations such as single-atom spin flips. Such investigations are crucial to the development of magnetic data storage devices at the ultimate size. However, very often the excitation cross sections in inelastic electron tunnelling are weak. Further, in vibrational spectroscopy out of the manifold of possible vibration modes only a few modes or even none are usually observed in the spectra. Selection rules have been developed to rationalize these observations in terms of the electronic structure of the adsorbate and substrate and the symmetry of the vibrational modes. The role of the tip, however, has scarcely been discussed – both experimentally and theoretically. The main target of this project is filling this gap by systematically investigating prototypical single-atom and single-molecule vibrational spectra with controllably modified tips.