范德华耦合双壁碳纳米管系统中一维物理的定量研究

项目名称： 范德华耦合双壁碳纳米管系统中一维物理的定量研究

项目编号： No.11474006

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 数理科学和化学

项目作者： 刘开辉

作者单位： 北京大学

项目金额： 90万元

中文摘要： 宏观体材料的性质主要由强化学键决定；低维纳米材料由于电子态主要分布在表面，弱范德华耦合可以对材料性质起到决定性影响。最近在范德华耦合的二维石墨烯\石墨烯、石墨烯\氮化硼双原子层中已经发现了新奇的范霍夫奇点态和霍夫施塔特蝴蝶图形效应。范德华耦合的一维体系中由于存在量子尺寸效应和增强的电子-电子多体相互作用，可能存在全新的一维物理现象。 本项目拟采用范德华耦合的一维模型体系双壁碳纳米管为研究对象，利用和发展透射电镜+超高灵敏度超快纳米光学技术原位研究单个碳纳米管水平上的手性结构和光谱，探索范德华电子耦合对一维体系电子结构的影响、激子-拉廷格液体相互作用、两层碳纳米管间超快电荷转移等一维物理问题。上述研究结果将为利用范德华作用调控碳纳米管的电子学、光学等物理性质和开发新一代碳纳米管基的纳米电子学、光子学器件提供理论基础。项目中发展的原位结构和光学性质测量方法也可以应用到其它低维纳米体系。

中文关键词： 一维物理；双壁碳纳米管；范德华；纳米光学；透射电镜

英文摘要： Nanoscale electronic coupling governs many important physical processes, ranging from charge separation in heterojunctions to energy transfer in photosynthesis. In bulk materials, such nanoscale coupling is usually achieved through strong chemical bonding. In low dimensional materials, van der Waals coupling can play an important role because electron waves are often exposed at the surfaces. Recently there has been tremendous interest to study emerging phenomena in van der Waals-coupled two-dimensional (2D) materials, such as van Hove singularity in twisted graphene bilayers and Hofstadter butterfly in graphene/boron nitride heterostructures. Physics in van der Waals-coupled one-dimensional (1D) materials can be equally rich and exciting, due to the unique strong quantum confinement and enhanced electron-electron interactions. Double-walled carbon nanotubes (DWNTs) provide an ideal family of model system to explore new 1D physics arising from van der Waals interactions. Here I propose to investigate novel 1D phenomena arising from van der Waals coupling in different DWNTs through a combination of single-tube level structural determination and high-contrast nano-optics/spectroscopy. In particular, we will focus on three exciting directions: (1) Electronic structure renormalization in incommensurate DWNTs (due to Van der Waals coupling); (2) Coupling between excitons and Luttinger liquid in metal/semiconductor DWNTs (i.e. DWNTs composed of a metallic outer wall and a semiconducting inner wall); (3) Ultrafast energy transfer between the inner- and outer-wall nanotubes. The understanding of electronic coupling in DWNTs can also lead to new ways to manipulate and control the electronic structure of 1D carbon nanotubes exploiting the van der Waals interactions. It may enable novel nanoelectronic and nanophotonic applications based on carbon nanotubes. In addition, the principles will be also applicable in other low-dimensional materials.

英文关键词： One-dimensional physics;Double-walled carbon nanotubes;Van der Waals;Nanooptics;Transmission electron microscope