In-situ Electrochemical Fabrication of Single Molecule Spintronic Junctions

自旋电子学代表了电子学的一个新方向，因为它利用了电子的自旋以及更熟悉的电子电荷。自旋是一种量子力学性质，其结果可以在材料的磁性行为中看到。自旋电子器件已经在生产中，例如，用于读取磁性硬盘上信息的传感器。然而，这些和大多数其他现有的自旋电子器件只由金属和氧化物制成，引入新材料将创造令人兴奋的新机会，本项目将研究有机分子如何集成到自旋电子器件中。使用有机分子代替传统的无机导体和绝缘体的原因部分是理论预测自旋可以以比其他材料更低的损耗传输，部分是有机化学提供了许多以有趣的方式改变分子性质的机会。我们将使最小的自旋电子器件成为可能，由单个分子连接的两个磁性金属触点组成，并测量它们的磁输运特性（电流如何受到磁场的影响）。一次研究一个分子消除了以前研究分子集合时发现的许多不确定性，例如，分子是否真的与金属接触化学结合。虽然具有挑战性，但可以使用扫描隧道显微镜测量通过单个分子的电流，这是一种可以控制两个金属触点分离的仪器，其精度小于单个原子的直径。在这个项目中，我们将通过开发新的电化学方法来改进以前的研究，使用离子液体（一种特殊类型的溶剂）。我们的新测量将比以前更快更干净。我们希望看到一系列有趣的行为，包括我们可以用外部电势控制的自旋输运，这将是晶体管的分子自旋电子学等价物。作为迈向实用自旋电子器件的一步，我们还将使用电化学和微电子工业中使用的一些技术，以基于明确定义的单层有机分子制造更坚固的自旋电子器件。

Spintronics represents a new direction for electronics as it exploits the spin of the electron as well as the more familiar electron charge. Spin is a quantum mechanical property, and its consequences are seen in the magnetic behaviour of materials. Spintronic devices are already in production, for example, the sensor used to read information on magnetic hard disks. However, these and most other existing spintronic devices are made only of metals and oxides.Introducing new materials will create exciting new opportunities, and this project will look at how organic molecules can be integrated into spintronic devices. The reason to use organic molecules in place of conventional inorganic conductors and insulators is partly that theory predicts that spin may be transported with lower loss than in other materials and partly that organic chemistry affords many opportunities for changing the properties of molecules in interesting ways. We will make the smallest spintronic devices possible, consisting of two magnetic metal contacts joined by a single molecule and measure their magneto-transport properties (how the electric current is affected by a magnetic field). Studying one molecule at a time removes many of the uncertainties found in previous studies of collections of molecules, where it was unclear, for example, whether the molecules were really bound chemically to the metal contacts. Though challenging it is possible to measure the current thorugh a single molecule using a scanning tunelling microscope, which is an instrument that can control the separation of two metal contacts with a precision of less than the diameter of a single atom . In this project we will improve on previous studies by developing new electrochemical methods, using ionic liquids (a special type of solvent). Our new measurements will be much faster and cleaner than was possible before. We expect to see a range of interesting behaviours, including spin transport that we can control with an external potential, This will be a molecular spintronic equivalent of the transistor. As a step towards a practical spintronic device, we will also use electrochemistry together with some of the technologies used in the microelectronics industry to make a more robust spintronic device based on a well-defined monolayer of organic molecules.