Theory of time-dependent nonequilibrium transport through a single molecule in a nonorthogonal basis set

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• 作者：Miloš S. Dražić ; Viktor Cerovski and Radomir Zikic
• 刊名：International Journal of Quantum Chemistry
• 出版年：2017
• 出版时间：January 5, 2017
• 年：2017
• 卷：117
• 期：1
• 页码：57-73
• 全文大小：1157K
• ISSN：1097-461X

文摘

A microscopic theory of nonequilibrium electronic transport under time-dependent bias through a molecule (or quantum dot) embedded between two semi-infinite metallic electrodes is developed in a nonorthogonal single-particle basis set using an ab initio formalism of Green's functions. The equilibrium zeroth order electron Green's function and self-energy are corrected by the corresponding time-inhomogeneous dynamical contributions derived in the Hartree approximation in a steady-state linear-response regime. Nonorthogonality contributes to dynamical response by introducing terms related to the central region-electrode interface, which appears only in the time-dependent case. The expression for current is also derived, where a nonorthogonality-induced dynamical correction gives an additional current that is not present in the orthogonal description. It is shown that the obtained expression for current is gauge-invariant and demonstrated that the omission of the additional current violates charge conservation. The additional current term vanishes in an orthogonal basis set.