Perpendicular-Current Spin-Polarized Transport Studies at Low Temperatures

这是一个实验凝聚态物理项目，研究金属磁性多层膜中的自旋极化电子输运。从基本和技术角度来看，这种传输都是有意义的。特别令人感兴趣的是电流几何，其中电子流垂直于多层膜的层，而不是面内电流流。垂直水流几何学是由密歇根州立大学的这个研究小组开创的。通过控制垂直几何中的磁序，该项目将解决四个研究课题：(1)两个非磁性金属之间或超导体内界面的自旋记忆损失；(2)壁阻和单个磁区的动力学：界面处的散射与电势阶跃和界面合金化的关系；以及(4)预测的交流约瑟夫森效应磁性模拟的实验实现。这项研究涉及最先进的仪器设备和研究生培训，为他们在信息存储技术、学术界或政府部门的各种职业做好准备。在十年的时间里，金属磁性多层膜中的巨磁电阻(GMR)已经从实验室发现转向商业设备(如计算机硬盘驱动器)的实际应用。进一步的进展需要更大的磁阻和更小的探测器。下一代探测器的候选者是多层中的GMR，用垂直于层的电流测量，这是密歇根州立大学的团队开创的一种几何学。这种几何形状有望在较小的样品中产生更大的磁阻。但根本性和实践性问题仍需解决。这项提案以新颖的方式解决了几个这样的问题。该研究计划为本科生和研究生提供使用最先进的仪器进行研究的机会，这将使他们为研究或技术，特别是信息存储技术的职业生涯做好准备。*

9820135PrattThis is and experimental Condensed Matter Physics project which studies spin-polarized electrical transport in metallic magnetic multilayers. This transport is of interest from both fundamental and technological viewpoints. Of particular interest is a current geometry where the electron flow is perpendicular to the layers of the multilayers, versus in-plane current flow. The perpendicular current geometry was pioneered by this research group at the Michigan State University. By controlling magnetic order in the perpendicular geometry, the project will address four research topics: (1) Spin-memory-loss at the interfaces between two non-magnetic metals or within superconductors; (2) Wall resistances and dynamics of individual magnetic domains: Relation of scattering at interfaces to potential steps and interfacial alloying; and (4) Experimental realization of a predicted magnetic analog of the AC Josephson effect. The research involve state of the art instrumentation and training for graduate students and prepares them for a variety of careers in information storage technology, academe or government.%%%In one decade, Giant Magneto-Resistance (GMR) in metallic magnetic multilayers has moved from a laboratory discovery to practical application in commercial devices such as hard disk drives found in computers. Further progress requires even larger magnetoresistance and even smaller detectors. A candidate for the next generation of detectors is GMR in multilayers measured with current flow perpendicular to the layers, a geometry pioneered by the group at Michigan State University. This geometry promises larger magnetoresistance in smaller samples. But both fundamental and practical issues still need to be resolved. This proposal addresses several such issues in novel ways. The research program provides undergraduate and graduate students opportunities to carry out research using state of the art instrumentation which will prepare them for careers in research or technology, particularly information storage technology.***