MECHANISM AND CONTROL OF TIP INDUCED ELECTRONIC AND ATOMIC PROCESSES

在这个项目中，我们的目的是从理论上阐明针尖和表面在纳米尺度空间中是如何相互作用的，以及这对瓷砖扫描探针显微镜的图像有何影响。此外，我们还试图为纳米结构的形成和控制奠定基础，并探索这种纳米结构的新性质。今年取得的主要成果包括以下几个方面。(1)阐述了非接触式原子力显微镜的成像机理和成像理论模拟方法的发展。(2)阐明了针尖与表面之间形成的原子桥和分子桥的量子输运特性。(3)系统地阐明了弹道电子在碳纳米管结中的传输系数。(4)阐明了针尖与表面的邻近效应对吸附原子的提取机理。(5)研究了绝缘层针尖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)发展了动态映像力理论，并将其应用于隧道障碍物的成因。

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.