单分子磁体隧道结中自旋相关的电子输运特性研究

Very recently, with the develop of molecular magnetic materials, the single magnetic-molecular (SMM) has been demonstrated as a appropriate candidate to the basic components of the molecule-based spintronic devices . Unlike other nano-particles, the SMM are molecules with a relatively large net spin moment and a significant uniaxial magnetic anisotropy . Below the block temperature,these molecules are trapped in one of the two metastable spin states . This bistability makes SMMs to be a suitable base for memory cells of future information storage and processing technology . So far, electronic tunneling spectra through the SMM have been experimentally demonstrated, and the spin dependent electronic transport properties through the SMM have also been extensively investigated, including magnetic signatures of the SMM in nonequilibrium condition, Kondo effect, the magnetization reversion, Berry phase and so on. In this program,we research the inelastic spin transport process between ltnerant electron and SMM''s magnetic core.We put forward a series of new molecular spintronic device function as spin filter，spin injector or molecule''s spin signal controller.This research theme also can afford us more physics pictures about spin-polarized tunneling process in SMM''s device . Such studies are valuable towards the development of nanoscale molecular spintronic devices based on electronic properties of the participating molecules.

随着磁性材料学的发展与进步，一种新型的分子材料-单分子磁体（ＳＭＭ）被公认能够成为未来自旋电子学器件的新宠儿。不同于普通的纳米颗粒材料，单分子磁体在即时仅有一个分子的情况下仍有较大的自旋角动量和明显的各向异性能。在低温状态下，磁性分子会稳定的保持在某个自旋态上并具有磁性。这种特性使磁性分子适合成为未来信息存储和处理的磁性单元。至今为止，大量的实验和理论工作都致力于研究单分子磁体中的电子输运，许多有趣的物理问题，诸如kondo效应，分子磁矩翻转，Berry相位等都在单分子磁体系统中讨论过。本项目在上述工作的基础上研究单分子磁体内的自旋电子输运问题，分析和讨论巡游电子与单分子磁体间的自旋相互作用以及其在分子器件中的应用，提供更多自旋过滤，注入和分子磁矩可操控方案。该项目研究帮助我们从物理原理上认识单分子磁体中自旋极化的输运行为，同时，也为设计和发展分子自旋纳米器件提供理论支持和研究思路。

借助GS（Giant Spin）理论模型，我们讨论了单分子磁体中的电子输运，研究了分子磁矩翻转，热自旋输运等效应在单分子磁体器件中的应用。本项目从量子力学基础的角度上研究单分子磁体内的自旋电子输运问题，分析和讨论巡游电子与单分子磁体间的自旋相互作用以及其在分子器件中的应用，提供一些自旋过滤，注入和分子磁矩可操控方案。同时我们将GS模型拓展到了两个分子的复杂结构,分析了由多个磁分子构成的电子器件内的自旋角动量转移行为。该项目研究不仅帮助我们更为清晰的认识了分子磁体与巡游电子之间的非弹性电子输运，同时，也为设计和发展分子自旋纳米器件提供思路与借鉴。