Describing the spin-polarized transport in molecular junctions by ab-initio calculations

通过从头计算描述分子连接中的自旋极化传输

• 批准号: 25247818
• 负责人: Dr. Daniel Wortmann
• 金额: --
• 依托单位: PGI-1 / IAS-1: Quanten-Theorie der Materialien
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2006
• 资助国家: 德国
• 起止时间: 2005-12-31 至 2011-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/25247818?language=en
• 关键词: Describing; spin; polarized; transport; molecular

Applying ab initio density functional theory we will study structural properties of simple organic molecules between metallic leads. Combining density functional theory with the nonequilibrium Green function approach we will investigate the spin-dependent transport properties in these systems. Our molecular system of choice will be the metal-benzene multipledecker sandwiches Xn(C6H6)m with paramagnetic transition-metal centers, X=V,Nb,Ta, as well as their functionalized derivatives, attached to Cu(111) leads. The transition-metal ion X in these molecules induces a magnetic moment and the spin-dependent conductance through the molecules will be studied as function of the ordering of these moments (ferromagnetic, antiferromagnetic, noncollinear), and of relative orientation of these moments with respect to the molecule leading to a ballistic anomalous magnetoresistance due to the effect of the spin-orbit interaction. Ferromagnetic CoCu(111) leads are explored as spin-injectors. Charging of the molecules as a function of the details of the absorption and the applied bias will be investigated including effects of the self-interaction correction beyond usual density functional theory methods.To achieve these goal the ab initio methods are developed in various directions including the implementation of an all-electron transport scheme for one-dimensional molecular structures attached to semi-infinite surfaces and a suitable scheme for the self-interaction correction.

应用从头算密度泛函理论，我们将研究简单有机分子在金属引线之间的结构性质。结合密度泛函理论和非平衡绿色函数方法，我们将研究这些体系中自旋相关的输运性质。我们选择的分子系统将是金属-苯多层夹心Xn（C6 H6）m，其具有顺磁性过渡金属中心，X=V，Nb，Ta，以及它们的官能化衍生物，连接到Cu（111）引线。在这些分子中的过渡金属离子X诱导磁矩和自旋相关的电导通过分子将被研究作为这些时刻的顺序的函数（铁磁，反铁磁，非共线），以及这些时刻相对于分子的相对取向导致弹道异常磁阻由于自旋轨道相互作用的影响。铁磁CoCu（111）引线被用作自旋注入器。为了实现这些目标，从头算方法在不同的方向上发展，包括对一维分子结构的全电子输运方案的实现，包括对连接到半导体上的分子结构的全电子输运方案的实现。无限表面和一个合适的计划的自相互作用校正。