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arXiv 0812.0867cond-mat.mes-hallcond-mat.mtrl-scicond-mat.other
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单分子异质结电子输运的多体理论

Many-body theory of electronic transport in single-molecule heterojunctions

J. P. Bergfield, C. A. Stafford

摘要:

建立了基于非平衡格林函数的分子结输运多体理论,该理论平等地对待相干量子效应和库仑相互作用。多体理论的中心量是结的库仑自能矩阵$Σ_{\rm C}$。$Σ_{\rm C}$是准确地评估在顺序隧道限制,和由于有限的隧道宽度的校正自洽地评估使用基于图形扰动理论的Keldysh轮廓守恒近似。我们的方法再现了库仑阻塞和相干传输制度的关键功能,同时在一个单一的统一的传输理论。作为我们理论的第一个应用,我们用半经验的$π$电子哈密顿量计算了苯二硫醇-金结的热电势和微分电导谱,该哈密顿量精确地描述了分子在8- 10 eV范围内的电子激发全谱。

英文摘要:

A many-body theory of molecular junction transport based on nonequilibrium Green's functions is developed, which treats coherent quantum effects and Coulomb interactions on an equal footing. The central quantity of the many-body theory is the Coulomb self-energy matrix $Σ_{\rm C}$ of the junction. $Σ_{\rm C}$ is evaluated exactly in the sequential tunneling limit, and the correction due to finite tunneling width is evaluated self-consistently using a conserving approximation based on diagrammatic perturbation theory on the Keldysh contour. Our approach reproduces the key features of both the Coulomb blockade and coherent transport regimes simultaneously in a single unified transport theory. As a first application of our theory, we have calculated the thermoelectric power and differential conductance spectrum of a benzenedithiol-gold junction using a semi-empirical $π$-electron Hamiltonian that accurately describes the full spectrum of electronic excitations of the molecule up to 8--10eV.

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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