Beijing Computational Science Research Center, Beijing 100084, China.
Sci Rep. 2013 Oct 23;3:3026. doi: 10.1038/srep03026.
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.
全计数统计对于深入理解纳米尺度器件中量子输运的基本物理过程至关重要。由于在实验中不可避免地存在探测器的反作用，因此探测器对纳米尺度器件的反作用也至关重要。在这里，我们研究了以量子点接触(QPC)形式的电荷探测器对偏置双量子点(DQD)的计数统计的反作用。我们表明，在某些条件下，这种不可避免的 QPC 诱导的反作用会对计数统计产生深远的影响，例如，将散粒噪声从亚泊松分布变为超泊松分布，以及将偏度从正变为负。此外，我们还表明，在探测器诱导的反作用下，通过增加 DQD 中两个单量子点能级之间的能量差，福勒因子和偏度都可以增强或抑制。
