Single Molecule Electronic Transport through Molecular Magnets

基于单分子的电和磁器件为电子器件的进一步小型化提供了令人兴奋的前景，在应用中具有潜在的巨大影响。到目前为止，几个实验已经显示出将单个分子连接到引线上并测量电传输的可能性。随着单分子磁体（SMM）设计的最新技术改进，结合联合收割机自旋和分子电子学的实验和装置变得现实。通过SMM传输提供了几个迄今为止尚未开发的独特功能：- SMM自然耦合到施加的外部磁场，因此可以用作磁传感器，开关或存储设备。- 在电极和SMM之间的弱耦合的限制下，输运效应和磁结构之间的强相互作用可以导致有趣的物理效应，例如电流辅助的自旋隧穿，导致Kondo效应的自旋涨落，磁库仑振荡和自旋累积。- 与有机系统相反，携带电流并且负责系统的磁性的分子轨道在空间上受到限制，即它们不太容易受到外部电场的影响。在这项调查中，我们计划开发微观模型来计算电子两端传输通过分子磁体在施加的磁场和电场的存在下，并确定通过这样一个系统的传输特性，电极和SMM之间的弱耦合，其中强库仑相关性和多体效应是重要的。

Electrical and magnetic devices based on single molecules offer exciting perspectives for the further minituarization of electronic devices with a potentially large impact in applications. To date several experiments have shown the possibility to attach individual molecules to leads and to measure the electrical transport. With recent technological improvements in the design of single-molecule magnets (SMM), experiments and devices that combine spin- and molecular electronics become realistic. Transport through SMM offers several unique features that have not been exploited to date: - SMM couple naturally to applied external magnetic fields and may thus function as magnetic sensors, switches or storage devices. - In the limit of weak coupling between electrodes and SMM a strong interaction between transport effects and magnetic structure can lead to interesting physical effects, such as current assisted spin-tunneling, spin fluctuations leading to Kondo effects, magneto-Coulomb-oscillations, and spin-accumulation. - In contrast to organic systems, the molecular orbitals which carry the current and which are responsible for the magnetic properties of the system are spatially confined, i.e. they are less susceptible to the influence of the external electric field. In this investigation we plan to develop microscopic models to calculate the electronic two-terminal transport though a molecular magnet in the presence of an applied magnetic and electric field and to determine the transport characteristics through such a system for weak coupling between electrode and SMM, where strong Coulomb correlations and many-body effects are important.