MECHANISM AND CONTROL OF TIP INDUCED ELECTRONIC AND ATOMIC PROCESSES

在这个项目中，我们的目的是澄清从理论方法如何在纳米尺度空间的尖端和表面相互作用，以及如何影响瓷砖扫描探针显微镜的图像。此外，我们也致力于建立纳米结构形成和控制的基础，并探索这种纳米结构的新特性。本年度取得的主要成果包括：(1)阐述了非接触式原子力显微镜的工作机理，发展了原子力显微镜成像的理论模拟方法。(2)通过原子桥和分子桥之间形成的尖端和表面的量子输运的详细功能被澄清。(3)系统地阐明了弹道电子通过碳纳米管结的传输系数。(4)阐明了针尖的邻近效应导致的吸附原子从表面上被抽离的机理。(5)研究了针尖绝缘表面缺陷的形成机理。(6)用第一性原理理论分析了原子线的形成及其磁性。(7)发展了动态镜像力理论，并将其应用于隧道势垒的起源。

In this project we aimed to clarify from theoretical approaches how the tip and the surface interact in the nano-scale space, and how this influences on the images of tile scanning probe microscopes. Moreover we also attemted to establish the basis of the formation and controle of the nano-structures and to explore novel properties of such nanO-structures. The major results obtained in this year include the followings. (1) The mechanism is elucidated for the non-contact mode atomic force microscope and the development of the theoretical simulation Method of the image. (2) Detailed features are clarified for the quantum transport through atomic bridges and molecular bridges formed between the tip and the surface. (3) Transmission coefficient of ballistic electrons through carbon-nanotube junctions is clarified in a systematic way. (4) Mechanism of the adatom extraction due to the proximity effect of the tip from the surface is elucidated. (5) Formation mechanism of the surface defects by the tip for the insulating surface is studied. (6) Formation of atomic wire and its magnetic properties are analysed by the first-principles theory. (7) Theory of the dynamic image force has been developed and applied to the origin of the tunnel barrier.