Shubin Nikolay M, Gorbatsevich Alexander A, Krasnikov Gennadiy Ya
P.N. Lebedev Physical Institute of the Russian Academy of Sciences, Moscow 119991, Russia.
JSC Molecular Electronics Research Institute, Zelenograd, Moscow 124460, Russia.
Entropy (Basel). 2020 Apr 17;22(4):459. doi: 10.3390/e22040459.
We study the transport properties of multi-terminal Hermitian structures within the non-equilibrium Green's function formalism in a tight-binding approximation. We show that non-Hermitian Hamiltonians naturally appear in the description of coherent tunneling and are indispensable for the derivation of a general compact expression for the lead-to-lead transmission coefficients of an arbitrary multi-terminal system. This expression can be easily analyzed, and a robust set of conditions for finding zero and unity transmissions (even in the presence of extra electrodes) can be formulated. Using the proposed formalism, a detailed comparison between three- and two-terminal systems is performed, and it is shown, in particular, that transmission at bound states in the continuum does not change with the third electrode insertion. The main conclusions are illustratively exemplified by some three-terminal toy models. For instance, the influence of the tunneling coupling to the gate electrode is discussed for a model of quantum interference transistor. The results of this paper will be of high interest, in particular, within the field of quantum design of molecular electronic devices.
我们在紧束缚近似下，运用非平衡格林函数形式研究了多端厄米结构的输运性质。我们表明，非厄米哈密顿量自然地出现在相干隧穿的描述中，并且对于推导任意多端系统的端到端传输系数的一般紧凑表达式是不可或缺的。该表达式易于分析，并且可以制定出一组稳健的条件来确定零传输和单位传输（即使存在额外电极）。使用所提出的形式体系，对三端和二端系统进行了详细比较，特别表明，连续统中束缚态的传输不会因插入第三电极而改变。主要结论通过一些三端玩具模型进行了说明性举例。例如，针对量子干涉晶体管模型讨论了隧穿耦合到栅电极的影响。本文的结果将特别引起分子电子器件量子设计领域的高度关注。
