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arXiv 1701.04515cond-mat.mes-hall
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能级简并度的增加对量子点结热电效率的大幅度提高

Large enhancement in thermoelectric efficiency of quantum dot junction due to increase of level degeneracy

David M T Kuo, Chih-Chieh Chen, Yia-Chung Chang

摘要:

从理论上证明了量子点(QD)结的优值($ZT$)可以显着提高时,参与电子输运的能级的简并程度增加。该理论是基于格林函数的方法在库仑阻塞制度,包括所有的关联函数产生的电子-电子相互作用与简并能级($L$)。我们发现,电导($G_e$)以及电子热导($κ_e$)是高度依赖于能级简并度($L$),而塞贝克系数($S$)不是。因此,当声子热导($κ_{ph}$)主导量子点结系统的热输运时,$ZT$的大幅增强主要归因于$G_e$的增加。在串联耦合双量子点的情况下,我们也得到了一个大的增强的$ZT$所产生的更高的$L$。与$G_e$和$κ_e$不同,发现$S$几乎与电子点间跳跃强度无关。

英文摘要:

It is theoretically demonstrated that the figure of merit ($ZT$) of quantum dot (QD) junctions can be significantly enhanced when the degree of degeneracy of the energy levels involved in electron transport is increased. The theory is based on the the Green-function approach in the Coulomb blockade regime by including all correlation functions resulting from electron-electron interactions associated with the degenerate levels ($L$). We found that electrical conductance ($G_e$) as well as electron thermal conductance ($κ_e$) are highly dependent on the level degeneracy ($L$), whereas the Seebeck coefficient ($S$) is not. Therefore, the large enhancement of $ZT$ is mainly attributed to the increase of $G_e$ when the phonon thermal conductance ($κ_{ph}$) dominates the heat transport of QD junction system. In the serially coupled double-QD case, we also obtain a large enhancement of $ZT$ arising from higher $L$. Unlike $G_e$ and $κ_e$, $S$ is found almost independent on electron inter-dot hopping strength.

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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