Phonon-assisted transport through quantum dots with normal and superconducting leads
Phonon-assisted transport through quantum dots with normal and superconducting leads
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DOI：
10.1103/physrevb.86.104513
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发表时间：
2012-09
影响因子：
3.7
通讯作者：
Sheng-Nan Zhang;Wei Pei;Tie-Feng Fang;Qing-feng Sun
中科院分区：
文献类型：
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作者：
Sheng-Nan Zhang;Wei Pei;Tie-Feng Fang;Qing-feng Sun
我们研究了通过耦合到正常和超导导线的振动量子点的电子输运。结果表明，在这样的系统中，库珀对和声子的相互作用会产生声子辅助的Andreev隧道效应。这些隧穿表现为共振峰分离的声子能量的一半，在电流中作为点水平的函数，而声子辅助正常隧穿产生的步骤分离的声子能量的电流作为偏置电压的函数。虽然这些步骤很容易通过增加温度而模糊，但发现峰是稳健的。我们的计算是从低压亚能隙区域到高压超能隙区域进行的，从而可以系统地探索引线中正常和BCS态密度下的声子辅助输运光谱。
We investigate electronic transport through a vibrating quantum dot coupled to a normal and a superconducting lead. It is shown that in such a system, the interplay of Cooper pairs and phonons gives rise to phonon-assisted Andreev tunnelings. These tunnelings manifest themselves as resonant peaks separated by a half of the phonon energy in the current as a function of the dot level, while phonon-assisted normal tunnelings produce steps separated by the phonon energy in the current as a function of the bias voltage. While the steps are easily smeared out by increasing the temperature, the peaks are found to be robust. Our calculation is performed from the low-voltage subgap regime to the high-voltage supergap regime, allowing an systematic exploration of the phonon-assisted transport spectroscopy subject to normal and BCS density of states in the leads.