Manipulating Multi-Spin Dynamics in Systems Targeting Organic Spintronics

化学结构，动力学和机制B（CSDM-B）计划支持教授迈克尔R。Wasielewski的西北大学进行基础研究，控制目标自旋电子学和量子信息处理的复杂多自旋分子系统的自旋动力学。具有特定供体-受体（D-A）距离和取向的共价连接的有机供体-受体分子内的快速光引发电子转移导致形成具有明确定义的初始自旋构型和磁性自旋-自旋相互作用的自旋纠缠电子-空穴对（即，自旋相关自由基离子对，SCRPs）。该项目的重点是在定制的共价结构中使用SCRPs控制有机分子阵列内的自旋相干性的苛刻任务。具体目标是研究：1）SCRP的光激发自旋相干转移的范围是什么？2)什么因素决定SCRP中的相干退相？3)相干自旋态能用SCRPs远距离传输吗？4)核自旋能被用来存储和恢复由SCRP产生的相干电子自旋态吗？发展一个基本的了解如何控制电荷和自旋输运通过有机分子的有序阵列是至关重要的新的电子学和自旋电子学的发展，特别是在其对计算机和信息处理的潜在影响。利用电子自旋的量子性质可能会导致先进的计算机技术在整个社会中具有广泛的应用。使用有机材料和生物启发的方法来解决这些问题提供了开发解决方案的可能性，这些解决方案不仅是通用的，而且是成本效益和环境友好的。

The Chemical Structure, Dynamics and Mechanism B (CSDM-B) program supports Professor Michael R. Wasielewski of Northwestern University to carry out fundamental studies on controlling the spin dynamics of complex multi-spin molecular systems that target spintronics and quantum information processing. Fast photo-initiated electron transfer within covalently-linked organic donor-acceptor molecules having specific donor-acceptor (D-A) distances and orientations results in the formation of spin-entangled electron-hole pairs (i.e. spin-correlated radical ion pairs, SCRPs) having well-defined initial spin configurations and magnetic spin-spin interactions. The project focuses on the demanding task of controlling spin coherence within organic molecular arrays using SCRPs in tailored covalent structures. The specific goals are to investigate: 1) What is the scope of spin coherence transfer by optical excitation of an SCRP? 2) What factors determine coherence dephasing in SCRPs? 3) Can coherent spin states be transported ("teleported") over long distances using SCRPs? 4) Can nuclear spins be used to store and retrieve coherent electron spin states produced by an SCRP? Developing a fundamental understanding of how to control charge and spin transport through organized arrays of organic molecules is critical to the development of new electronics and spintronics especially with regard to their potential impact on computers and information processing. Taking advantage of the quantum nature of electron spin may lead to advanced computer technologies with broad applications throughout society. The use of organic materials and bio-inspired approaches to these problems offers the possibility of developing solutions that are not only versatile, but are cost effective and environmentally benign as well.