Nonlinear conductance and negative differential resistance of nanowires: A combined model and ab-initio theory

本提案的目的是研究悬浮金属链（纳米接触）的输运性质。采用基于密度泛函理论的从头算方法对系统进行了描述。利用格林函数方法，我们能够描述悬浮在两个半无限引线之间的纳米线。根据兰道尔理论，在弹道极限下进行输运计算。导线中原子的结构弛豫被充分考虑在内。对金属和铁磁系统进行了研究。通过计算，我们可以深入了解纳米接触电导背后的微观过程。

The aim of this proposal is the investigation of transport properties of suspended metallic chains (nanocontacts). The systems are described by means of an ab initio method based on density functional theory. Using a Greens function method we are able to describe the nanowire suspended between two semi-infinite leads. The transport calculations are performed in the ballistic limit based on Landauer theory. The structural relaxation of the atoms in the wire is fully taken into account. The investigations are performed for metallic and ferromagnetic systems. The calculations allow an material-specific insight into the microscopic processes behind the conductance of a nanocontact.