Detector-induced backaction on the counting statistics of a double quantum dot
Detector-induced backaction on the counting statistics of a double quantum dot
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DOI：
10.1038/srep03026
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发表时间：
2012-10
影响因子：
4.6
通讯作者：
Zeng-Zhao Li;C. Lam;Ting Yu;J. You
中科院分区：
文献类型：
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作者：
Zeng-Zhao Li;C. Lam;Ting Yu;J. You
电子输运的全计数统计对于更深入地理解纳米级器件中量子输运的基本物理过程具有重要意义。由于在实验中不可避免的存在，探测器对纳米级器件的反作用力也是必不可少的。本文研究了以量子点接触（QPC）形式存在的电荷探测器对偏置双量子点计数统计量的反作用。我们表明，在某些条件下，这种不可避免的qpc诱导的反作用力会对计数统计产生深远的影响，例如，将射击噪声从亚泊松变为超泊松，将偏度从正变为负。此外，我们还表明，在探测器诱导的反向作用下，通过增加DQD的两个单点能级之间的能量差，可以增强或抑制Fano因子和偏度。
Full counting statistics of electron transport is of fundamental importance for a deeper understanding of the underlying physical processes in quantum transport in nanoscale devices. The backaction effect from a detector on the nanoscale devices is also essential due to its inevitable presence in experiments. Here we investigate the backaction of a charge detector in the form of a quantum point contact (QPC) on the counting statistics of a biased double quantum dot (DQD). We show that this inevitable QPC-induced backaction can have profound effects on the counting statistics under certain conditions, e.g., changing the shot noise from being sub-Poissonian to super-Poissonian and changing the skewness from being positive to negative. Also, we show that both Fano factor and skewness can be either enhanced or suppressed by increasing the energy difference between two single-dot levels of the DQD under the detector-induced backaction.