Supramolecular spin valves
Supramolecular spin valves
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DOI：
10.1038/nmat3050
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发表时间：
2011-07-01
期刊：
影响因子：
41.2
通讯作者：
Wernsdorfer, W.
中科院分区：
文献类型：
--
作者：
Urdampilleta, M.;Klyatskaya, S.;Wernsdorfer, W.
磁性分子是设计自旋电子器件的潜在构建块（1，2）。此外，分子材料使得自下而上的处理技术能够与例如传统的自上而下的纳米纤维（3）相结合。基于巨磁电阻（4）、隧道磁电阻（5）和自旋阀效应（6）的固态自旋电子器件的发展已经彻底改变了磁存储器的应用。最近，在有机半导体隧道结中已经观察到自旋弛豫时间的显著改善（7，8），耦合到磁性电极的单个非磁性分子已经显示出巨磁阻（9，10），并且已经提出了利用单分子磁体的量子隧穿性质的混合器件（2）。在这里，我们提出了一个原始的自旋阀器件，其中的一个单壁碳纳米管与非磁性电极接触，是横向耦合通过超分子相互作用的TbPc 2单分子磁铁（Pc =酞菁）的单分子量子点。它们的局部磁矩导致通过单壁碳纳米管的电输运的磁场依赖性，导致在低于1 K的温度下的磁阻比高达300%。因此，我们证明了一个超分子自旋阀的功能，没有磁引线。我们的研究结果开辟了新的自旋电子器件的量子特性的前景。
Magnetic molecules are potential building blocks for the design of spintronic devices(1,2). Moreover, molecular materials enable the combination of bottom-up processing techniques, for example with conventional top-down nanofabrication(3). The development of solid-state spintronic devices based on the giant magnetoresistance(4), tunnel magnetoresistance(5) and spin-valve effects(6) has revolutionized magnetic memory applications. Recently, a significant improvement of the spin-relaxation time has been observed in organic semiconductor tunnel junctions(7,8), single non-magnetic molecules coupled to magnetic electrodes have shown giant magnetoresistance(9,10) and hybrid devices exploiting the quantum tunnelling properties of single-molecule magnets have been proposed(2). Herein, we present an original spin-valve device in which a nonmagnetic molecular quantum dot, made of a single-walled carbon nanotube contacted with non-magnetic electrodes, is laterally coupled through supramolecular interactions to TbPc2 single-molecule magnets (Pc = phthalocyanine). Their localized magnetic moments lead to a magnetic field dependence of the electrical transport through the single-walled carbon nanotube, resulting in magnetoresistance ratios up to 300% at temperatures less than 1 K. We thus demonstrate the functionality of a supramolecular spin valve without magnetic leads. Our results open up prospects of new spintronic devices with quantum properties.