多壁纳米碳管中的AAS效应研究

分析研究了多壁纳米碳管中的AAS效应．通过给出多壁纳米碳管中电子的多圈(通道)分波波函数的量子干涉模型，在AAS理论的框架下推出了多壁纳米碳管磁电阻的解析表达式．研究还发现由于多壁纳米碳管壁间的相互作用，多壁纳米碳管中电子的输运性质是扩散型的，存在着一个确定的相位相干长度．有限的相位相干长度用在磁电阻公式中可以解释最新的几个多壁纳米碳管中的磁电阻实验，如典型的负磁阻效应、磁电阻随外加磁场的高阶周期震荡等．

Study on AAS Effect on Multiwalled Carbon Nanotubes

We have studied the AAS effect on the magnetoresistance(MR) in multiwalled carbon nanotubes. By giving a multiple\|cycle quantum interference model we have obtained magnetoresistance expression in the framework of the AAS theory. We find that the electron transportation property in multiwalled carbon nanotube is diffusive because of the interaction between the walls. The MR expression based upon finite phase\|breaking length can explain several experimental results about distinct negative magnetoresistance of carbon nanotubes. The higher\|order oscillation peaks with magnetic flux existed in the MR can also be explained by our model. And a new method to measure the phase\|breaking has been suggested.