‡Key Laboratory for the Physics and Chemistry of Nanodevices, Department of Electronics, Peking University, Beijing 100871, China.
§Zhejiang Key Laboratory for Reactive Chemistry on Solid Surfaces, Institute of Physical Chemistry, Zhejiang Normal University, Jinhua 321004, China.
J Am Chem Soc. 2015 May 13;137(18):5923-9. doi: 10.1021/ja512483y. Epub 2015 Apr 29.
We report an electrochemically assisted jump-to-contact scanning tunneling microscopy (STM) break junction approach to create reproducible and well-defined single-molecule spintronic junctions. The STM break junction is equipped with an external magnetic field either parallel or perpendicular to the electron transport direction. The conductance of Fe-terephthalic acid (TPA)-Fe single-molecule junctions is measured and a giant single-molecule tunneling anisotropic magnetoresistance (T-AMR) up to 53% is observed at room temperature. Theoretical calculations based on first-principles quantum simulations show that the observed AMR of Fe-TPA-Fe junctions originates from electronic coupling at the TPA-Fe interfaces modified by the magnetic orientation of the Fe electrodes with respect to the direction of current flow. The present study highlights new opportunities for obtaining detailed understanding of mechanisms of charge and spin transport in molecular junctions and the role of interfaces in determining the MR of single-molecule junctions.
我们报告了一种电化学辅助的跳转接触扫描隧道显微镜（STM）断接方法，以创建可重复且定义良好的单分子自旋电子学结。STM 断接配备了一个与电子输运方向平行或垂直的外磁场。我们测量了 Fe-对苯二甲酸（TPA）-Fe 单分子结的电导，在室温下观察到高达 53%的巨大单分子隧道各向异性磁阻（T-AMR）。基于第一性原理量子模拟的理论计算表明，Fe-TPA-Fe 结的观察到的 AMR 源自 TPA-Fe 界面处的电子耦合，该电子耦合由 Fe 电极相对于电流方向的磁取向所修饰。本研究为深入了解分子结中电荷和自旋输运的机制以及界面在确定单分子结的 MR 方面的作用提供了新的机会。
