Spin dynamics in magnetic nanostructures

21世纪材料科学的主要进展将是基于控制纳米结构杂化和复合系统。在磁学中，这条道路始于80年代初。超高压制备复杂的异质磁性多层结构和超晶格使人们能够创造出独特的磁性材料。这一领域的成功发生得非常快，并导致了新的革命性的设备应用。电子的自旋，而不是它的电荷，在电子学中创造了非凡的机会，被称为自旋电子学。事实上，2007年的诺贝尔奖是由彼得·格伦伯格和阿尔伯特·费特因发现巨磁电阻(GMR)而颁发的。为了继续在这一领域取得快速进展，需要在理解纳米几何中的自旋相互作用方面取得进展。我使用分子束外延(MBE)来沉积超薄膜和超晶格。利用射频、穆斯堡尔谱、直流谱和皮秒分辨磁光、电子输运技术和电子显微镜技术研究了磁性和自旋相关电子输运性质。我们的研究涉及自旋动力学，重点是自旋流的研究。在铁磁-隧道结-正常金属界面处的强电子关联效应可以将自旋泵浦提高到原来的十倍。在这一点上，人们可以开始考虑基于不伴随电荷净流动的纯自旋流来发展信息处理。我们将开发一种使用高功率自旋电流的自旋电池。我们将测试和优化铁磁性金属和半导体之间的自旋注入，使我们有机会开发出高效的自旋晶体管。这项工作将由SFU、UBC、U·Edmonton、McGill U、Max-Planck Institute Halle、U·Regensburg和U·Delware的科学家共同努力完成，使我们能够涵盖半导体、结构科学、磁光、器件制造和计算机模拟方面的广泛专业知识。与UBC、TRIUMF、U.Edmonton和McGill U的合作是加拿大高级研究院(CIFAR)计划的一部分。

The main advances in materials science in the 21st century are going to be based on controlling nanostructured hybrid and composite systems. In magnetism this path started in the early eighties. UHV fabrication of complex heterogeneous magnetic multilayer structures and superlattices has allowed one to create unique magnetic materials. The success in this field has occurred very quickly and has led to new and revolutionary device applications. The spin of the electron rather than its charge has created remarkable opportunities in electronics, coined spintronics. In fact the Nobel Prize for 2007 was awarded for the discovery of Giant Magnetoresistance (GMR) by Peter Gruenberg and Albert Fert. To continue the rapid progress in this field requires advances in the understanding of spin interactions in nanoscopic geometries. I use Molecular Beam Epitaxy (MBE) for the deposition of ultrathin films and superlattices. Radio frequency, Mossbauer, dc and pico second time resolved magneto-optical, electron transport techniques and electron microscope techniques are employed to identify magnetic and spin dependent electron transport properties. Our studies involve spin dynamics with emphasis on the study of spin currents. Strong electron correlation effects at the ferromagnet-tunneling junction-normal metal interfaces can enhance spin pumping by a factor of ten. At this point one can start to think about developing information processing based on pure spin currents which are not accompanied by the net flow of electric charge. We are going to develop a spin battery using high power spin currents. We will test and optimize the spin injection between ferromagnetic metals and semiconductors giving us an opportunity to develop an efficient spin-transistor. This work will be done in a collaborative effort involving scientists at SFU, UBC, U. Edmonton, McGill U., Max-Planck Institute Halle, U. Regensburg, and U. Delaware allowing us to cover a wide range of expertise in semiconductors, structural science, magneto-optics, device fabrication, and computer simulations. The cooperation with UBC, TRIUMF, U. Edmonton, and McGill U. are a part of Canadian Institute For Advanced Research (CIFAR) program.