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Mesoscopic phenomena in fine structures fabricated by nano-porous Alumina membranes

纳米多孔氧化铝膜精细结构中的介观现象

基本信息

批准号：
11440115
负责人：
HARUYAMA Junji
金额：
$ 9.09万
依托单位：
Aoyama Gakuin University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B).
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-11440115/
关键词：
mesoscopic phenomena nano-porous Alumina membrane single electron tunneling single nano-tunnel junction external electromagnetic environment localization Carbon nanotube macroscopic quantum tunneling 弱局在磁気抵抗

项目摘要

The goal of this research project was to find novel quantum-mesoscopic phenomena, unobservable in the past nanostrutures fabricated by semiconductor nano-technologies, in unique nanostrucures fabricated by nano-porous Alumina membranes. The following things were successfully observed.1.Coulomb blockade (CB) in an array of single nano-tunnel junctions/high-impedance quantum-wires. We connected Ni-nanowires with electron-electron interaction following Altshuler's theory and multi-walled carbon nanotubes (MWNT) with localization, phase interference effect of electron waves, to single nano-tunnel junctions. CB, different between the structures, was successfully observed. We pointed out that phase fluctuation energy caused by electron-electron interaction and charging energy were the key for the Ni-wires/single junctions system. In contrast, we provided a question, "Is energy dissipation in high-impedance external environment actually indispensable to yield CB in single junction systems? ", in MWNTs/single junction systems. It was because localization, yielding CB, was an elastic phenomenon.2.Successful fabrication of MWNTs into Alumina membranes. We found that phase interference of electron waves in the MWNTs was very sensitive to the impurities on the top end of the MWNTs with only 5% in volume ratio. It was firstly found that spin-orbit interaction in heavy-mass impurities (Au, Pt) changed the weak localization in MWNTs to the anti localization.3.Successful observation of abrupt magnetoresistnce (MR) jumps originated from macroscopic quantum tunneling (MQT) of magnetic domain walls, in Ni-nanowires., by detailed measurements. Correlation of the MQT with weak localization was also firstly investigated.4.MR oscillation measured among the Ni-quantum wires and dependence of coecivity on Ni-wire diameter.

本研究项目的目标是在纳米多孔氧化铝膜制造的独特纳米结构中发现新的量子介观现象，这些现象在过去由半导体纳米技术制造的纳米结构中无法观察到。成功地观察到了以下几点：单纳米隧道结/高阻抗量子线阵列中的库仑阻滞（CB）。我们根据Altshuler理论将具有电子-电子相互作用的ni纳米线与具有电子波相位干涉效应的多壁碳纳米管（MWNT）连接到单纳米隧道结上。成功地观察到不同结构的CB。指出电子-电子相互作用引起的相涨落能和充电能是镍线/单结体系的关键。相反，我们提出了一个问题，“高阻抗外部环境中的能量耗散对于单结系统的产生CB是否必不可少？”，在MWNTs/单结系统中。这是因为局部化（产生CB）是一种弹性现象。纳米碳管在氧化铝膜中的成功制备。我们发现，纳米碳管中电子波的相位干涉对纳米碳管顶端的杂质非常敏感，其体积比仅为5%。首次发现，重质量杂质（Au, Pt）中的自旋轨道相互作用使MWNTs的弱局域化转变为反局域化。成功观察了镍纳米线中磁畴壁宏观量子隧穿（MQT）引起的磁电阻突变（MR）跃变。通过详细的测量。同时也首次研究了弱定位与MQT的相关性。测量了镍量子线之间的磁流变振荡及其相干度与镍量子线直径的关系。