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arXiv 0709.2480cond-mat.mes-hall
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缺陷金属单壁碳纳米管的Aharonov-Bohm微分电导调制

Aharonov-Bohm differential conductance modulation in defective metallic single-wall carbon nanotubes

Mehran Bagheri

备注：
11 pages, 4 figures
发表信息：
J. Phys.: Condens. Matter, 20, 075227(2008)
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摘要：

采用微扰方法研究了Aharonov-Bohm（AB）磁通诱导的能隙对缺陷金属单壁碳纳米管（MSWCNTs）输运性质的影响.电子波被一对杂质来回散射，产生法布里-珀罗振荡，构成相干后向散射干涉图样（CBSIP）。结果表明，通过施加平行于纳米管轴向的磁场，CBSIP被非周期性调制。事实上，AB通量通过额外的相移来控制该CBSIP。因此，CBSIP的极值以及零点位于量$Φ_ρ=Φ/{Φ_0}$的无理分数处，其中$Φ$是穿透纳米管横截面的通量，而$Φ_{0}=h/e$是磁量子通量。实际上，磁微分电导（MDC）分布中的两个相邻极值之间的间距随着磁场的增加而减小。金属锯齿形和扶手椅形纳米管分别获得更快更高和更慢更短的变化。这些结果表明，有缺陷的金属纳米管可以用作基于AB效应的磁导开关器件。

英文摘要：

Using a perturbative approach, the effects of the energy gap induced by the Aharonov-Bohm (AB) flux on the transport properties of defective metallic single-walled carbon nanotubes (MSWCNTs) are investigated. The electronic waves scattered back and forth by a pair of impurities give rise to Fabry-Perot oscillations which constitutes a coherent backscattering interference pattern (CBSIP). It is shown that, the CBSIP is aperiodically modulated by applying a magnetic field parallel to the nanotube axis. In fact, the AB-flux brings this CBSIP under control by an additional phase shift. As a consequence, the extrema as well as zeros of the CBSIP are located at the irrational fractions of the quantity $Φ_ρ=Φ/{Φ_0}$, where $Φ$ is the flux piercing the nanotube cross section and $Φ_{0}=h/e$ is the magnetic quantum flux. Indeed, the spacing between two adjacent extrema in the magneto-differential conductance (MDC) profile is decreased with increasing the magnetic field. The faster and higher and slower and shorter variations is then obtained by metallic zigzag and armchair nanotubes, respectively. Such results propose that defective metallic nanotubes could be used as magneto-conductance switching devices based on the AB effect.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

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