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arXiv 1307.0946cond-mat.mes-hall
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单分子量子点的全计数统计

Full counting statistics of a single-molecular quantum dot

Bing Dong, G. H. Ding, X. L. Lei

摘要:

研究了与局域声子强耦合、与两个金属电极弱隧穿连接的单个量子点的全计数统计。利用广义非平衡格林函数方法和Lang-Firsov变换,我们导出了累积量母函数的显式解析公式,使我们能够区分弹性和非弹性对电流和零频散粒噪声的贡献。我们发现,在零温度下,非弹性效应导致向上的步骤中的电流和向下跳跃的噪声在偏置电压对应的非弹性通道的开放,这是由于振动引起的复杂的依赖性的能量和偏置电压上的电子自能。更有趣的是,Fano因子随着偏置电压的增加而呈现振荡行为,并且观察到其最小值小于一半。

英文摘要:

We investigate the full counting statistics of a single quantum dot strongly coupled to a local phonon and weakly tunnel-connected to two metallic electrodes. By employing the generalized nonequilibrium Green function method and the Lang-Firsov transformation, we derive an explicit analytical formula for the cumulant generating function, which makes one to be able to identify distinctly the elastic and inelastic contributions to the current and zero-frequency shot noise. We find that at zero temperature, the inelastic effect causes upward steps in the current and downward jumps in the noise at the bias voltages corresponding to the opening of the inelastic channels, which are ascribed to the vibration-induced complex dependences of electronic self-energies on the energy and bias voltage. More interestingly, the Fano factor exhibits oscillatory behavior with increasing bias voltage and its minimum value is observed to be smaller than one half.

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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