Long electron dephasing length and disorder-induced spin-orbit coupling in indium tin oxide nanowires
Long electron dephasing length and disorder-induced spin-orbit coupling in indium tin oxide nanowires
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DOI：
10.1103/physrevb.82.195429
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发表时间：
2010-10
影响因子：
3.7
通讯作者：
Yao-Wen Hsu;S. Chiu;A. Lien;Juhn-Jong Lin
中科院分区：
文献类型：
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作者：
Yao-Wen Hsu;S. Chiu;A. Lien;Juhn-Jong Lin
利用四探针组态法测量了两条氧化铟锡（ITO）纳米线在0.25 ~ 40 K温度范围内的量子干涉磁阻效应。与一维弱（反）局域化理论的磁阻比较，提取电子退相长度L\phi$。我们发现，在一个60纳米直径的纳米线与低电阻率的$\rho$（10 K）= 185 $\mu \Omega$ cm，$L\phi$是长的，从150 nm在40 K增加到520 nm在0.25 K。因此，纳米线显示出严格的一维弱局域化效应，可达几十开尔文。在第二个72纳米直径的纳米线与高电阻率的$\rho$（10 K）= 1030 $\mu \Omega$ cm，退相长度被抑制到$L\phi$（0.26 K）= 200 nm，因此，交叉的有效器件维数从1到3发生在约12 K。特别地，在后一种样品中，无序诱导的自旋轨道耦合是明显的，在低于4K的温度下表现出弱的反定域效应这些观察结果表明，通过控制不同水平的原子缺陷和杂质，可以在ITO纳米线中实现多功能的量子干涉效应。
We have measured the quantum-interference magnetoresistances in two single indium tin oxide (ITO) nanowires between 0.25 and 40 K, by using the four-probe configuration method. The magnetoresistances are compared with the one-dimensional weak-(anti)localization theory to extract the electron dephasing length $L_\phi$. We found, in a 60-nm diameter nanowire with a low resistivity of $\rho$(10 K) = 185 $\mu \Omega$ cm, that $L_\phi$ is long, increasing from 150 nm at 40 K to 520 nm at 0.25 K. Therefore, the nanowire reveals strict one-dimensional weak-localization effect up to several tens of degrees of Kelvin. In a second 72-nm diameter nanowire with a high resistivity of $\rho$(10 K) = 1030 $\mu \Omega$ cm, the dephasing length is suppressed to $L_\phi$(0.26 K) = 200 nm, and thus a crossover of the effective device dimensionality from one to three occurs at about 12 K. In particular, disorder-induced spin-orbit coupling is evident in the latter sample, manifesting weak-antilocalization effect at temperatures below $\sim$ 4 K. These observations demonstrate that versatile quantum-interference effects can be realized in ITO nanowires by controlling differing levels of atomic defects and impurities.