论文标题
非平衡绿色功能（NEGF）方法
The Non-Equilibrium Green Function (NEGF) Method
论文作者
论文摘要
非平衡绿色函数（NEGF）方法是在1960年代通过Schwinger，Kadanoff，Baym，Keldysh等经典作品在1960年代建立的，并使用多体扰动理论（MBPT）和非平衡过程的图解理论建立了。许多文献都是基于原始的基于MBPT的方法，这使得那些不熟悉高级量子统计力学的人无法访问。我们使用相对基本的参数直接从单电子Schrödinger方程中获得NEGF方程。这些方程已被用来讨论许多引起极大兴趣的问题，例如量化电导，（整数）量子大厅效应，安德森定位，共振隧道和自旋运输，而无需系统地处理多体效应。但是，它超越了纯粹的连贯运输，使我们能够在一个自矛盾的天生近似值中包括分阶段的相互作用（动量 - 重汇率和控制动量以及旋转和自旋 - 重新递延）。我们认为，NEGF方程的范围和效用超过了最初用于推导它的基于MBPT的方法。 Negf教我们如何将量子动力学与“接触”结合在一起，就像Boltzmann教会了我们如何使用广泛的，具有象征意义的词联系人表示各种熵驱动的过程。我们认为，这种“接触”的方法对于从事设备物理学或非平衡统计力学的任何人来说，Schrödinger方程都应该引起广泛的兴趣。
The Non-Equilibrium Green Function (NEGF) method was established in the 1960's through the classic work of Schwinger, Kadanoff, Baym, Keldysh and others using many-body perturbation theory (MBPT) and the diagrammatic theory for non-equilibrium processes. Much of the literature is based on the original MBPT-based approach and this makes it inaccessible to those unfamiliar with advanced quantum statistical mechanics. We obtain the NEGF equations directly from a one-electron Schrödinger equation using relatively elementary arguments. These equations have been used to discuss many problems of great interest such as quantized conductance, (integer) quantum Hall effect, Anderson localization, resonant tunneling and spin transport without a systematic treatment of many-body effects. But it goes beyond purely coherent transport allowing us to include phase-breaking interactions (both momentum-relaxing and momentum-conserving as well as spin-conserving and spin-relaxing) within a self-consistent Born approximation. We believe that the scope and utility of the NEGF equations transcend the MBPT-based approach originally used to derive it. NEGF teaches us how to combine quantum dynamics with "contacts" much as Boltzmann taught us how to combine classical dynamics with "contacts", using the word contacts in a broad, figurative sense to denote all kinds of entropy-driven processes. We believe that this approach to "contact-ing" the Schrödinger equation should be of broad interest to anyone working on device physics or non-equilibrium statistical mechanics in general.
