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arXiv 1202.1329cond-mat.mes-hall
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铟锡氧化物纳米线的普适电导涨落

Universal conductance fluctuations in indium tin oxide nanowires

Ping-Yu Yang, L. Y. Wang, Yao-Wen Hsu, Juhn-Jong Lin

摘要:

从0.26 K到$\sim 25$ K,在弱无序氧化铟锡纳米线中观察到了与磁场相关的普适电导涨落(UCF).随着温度的降低,涨落幅度增加,在$T \lesssim 1$ K时达到$e^2/h$的一部分。UCF图案的形状被发现是非常敏感的样品的热循环到室温,这会导致不可逆的杂质重新配置。另一方面,UCF幅度对热循环不敏感。我们测量的均方根UCF幅度的温度依赖性与现有的理论[C。W. Beenakker和H. van Houten,Phys.Rev.B \textbf{37},6544(1988)]。一个显着的差异被发现,这似乎意味着,实验的UCF的不切断的热扩散长度$L_T$,如预期的理论预测时,$L_T < L_φ$,其中$L_φ$是电子退相长度。近似的电子退相长度推断UCF的幅度,并与提取的弱本地化磁阻研究。观察到合理的半定量协议。

英文摘要:

Magnetic field dependent universal conductance fluctuations (UCF's) are observed in weakly disordered indium tin oxide nanowires from 0.26 K up to $\sim 25$ K. The fluctuation magnitudes increase with decreasing temperature, reaching a fraction of $e^2/h$ at $T \lesssim 1$ K. The shape of the UCF patterns is found to be very sensitive to thermal cycling of the sample to room temperatures, which induces irreversible impurity reconfigurations. On the other hand, the UCF magnitudes are insensitive to thermal cycling. Our measured temperature dependence of the root-mean-square UCF magnitudes are compared with the existing theory [C. W. J. Beenakker and H. van Houten, Phys. Rev. B \textbf{37}, 6544 (1988)]. A notable discrepancy is found, which seems to imply that the experimental UCF's are not cut off by the thermal diffusion length $L_T$, as would be expected by the theoretical prediction when $L_T < L_φ$, where $L_φ$ is the electron dephasing length. The approximate electron dephasing length is inferred from the UCF magnitudes and compared with that extracted from the weak-localization magnetoresistance studies. A reasonable semiquantitative agreement is observed.

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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