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arXiv 0901.3178cond-mat.mes-hallcond-mat.str-el
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量子点接触中的电导反常与Fano因子的降低

Conductance Anomaly and Fano Factor Reduction in Quantum Point Contacts

Shuji Nakamura, Masayuki Hashisaka, Yoshiaki Yamauchi, Shinya Kasai, Teruo Ono, Kensuke Kobayashi

摘要:

报道了一种电导异常可由栅电极静电调节的量子点接触(QPC)的散粒噪声和直流输运特性的实验研究。通过控制单个QPC使其在$0.5 G_0$、$0.8 G_0$或$0.9 G_0$($G_0 = 2e^2/h$)处无异常或有异常,我们证明了在电导低于$G_0$时,由于两个自旋相关通道的非对称传输,异常总是伴随着Fano因子的降低.对于QPC调谐有异常在$0.5 G_0$的通道不对称性被发现是高达67%的自旋能隙逐渐演变的电导增加。

英文摘要:

We report an experimental study on the shot noise as well as the dc transport properties of a quantum point contact (QPC) whose conductance anomaly can be tuned electrostatically by the gate electrodes. By controlling the single QPC so that it has no anomaly or an anomaly at $0.5 G_0$, $0.8 G_0$ or $0.9 G_0$ ($G_0 = 2e^2/h$), we prove that the anomaly always accompanies the Fano factor reduction due to the asymmetric transmission of the two spin-dependent channels for the conductance lower than $G_0$. For the QPC tuned to have the anomaly at $0.5 G_0$ the channel asymmetry is found to be as large as 67% with the spin gap energy gradually evolving as the conductance increases.

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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