论文标题
相互作用系统的Landauer公式：一致的非扰动近似
Landauer formula for interacting systems: a consistent non-perturbative approximation
论文作者
论文摘要
运输测量是表征化学和物理学中小型系统的最广泛使用的方法之一。当相互作用可忽略不计时，可以使用Landauer公式获得通过量子点，纳米线，分子连接和其他亚微米结构的电流。 Meir和Wingreen得出了在相互作用存在下也适用电流的精确表达。这种强大的理论工具需要了解确切的绿色功能。到目前为止，缺少超出直接有限级扰动理论的近似值。在这里，我们为电流和热电流提供一般表达式，其中我们将自能源扩展到最低阶（经常被称为GW近似），但对此数量的所有订单保持贡献。此外，我们表明仅当正确包括自我能源和顶点校正时，电流才保存。我们证明我们的公式捕获了重要的非扰动特征，因此在找不到精确解决方案的情况下提供了强大的工具。
Transport measurements are one of the most widely used methods of characterizing small systems in chemistry and physics. When interactions are negligible, the current through quantum dots, nanowires, molecular junctions, and other submicron structures can be obtained using the Landauer formula. Meir and Wingreen derived an exact expression for the current that also applies in the presence of interactions. This powerful theoretical tool requires knowledge of the exact Green's function. So far, an approximation extending beyond direct finite-order perturbation theory is missing. Here, we provide general expressions for both the electric and thermal currents where we expand the self-energy to the lowest order (frequently dubbed the GW approximation) but keep contributions to all orders in this quantity. Moreover, we show that the electric current is conserved only when the self-energy and vertex corrections are correctly included. We demonstrate that our formulae capture important non-perturbative features and hence, provide a powerful tool in cases where the exact solution cannot be found.
