Perpendicular-Current Spin-Polarized Transport Studies at Low Temperatures

这是一个凝聚态物理实验项目，研究金属磁性多层中的自旋极化电输运。从基础和技术的角度来看，这种传输都很有趣。特别有趣的是电流几何，其中电子流垂直于多层的层，而不是平面内电流。垂直电流几何是由密歇根州立大学的这个研究小组首创的。通过控制垂直几何结构中的磁顺序，该项目将解决四个研究课题：(1)两种非磁性金属之间或超导体内部界面的自旋记忆丢失；(2)单个磁畴的壁阻和动力学：界面散射与电位步长和界面合金化的关系；(4)实验实现了预测的交流约瑟夫森效应的磁模拟。这项研究涉及最先进的仪器和研究生的培训，为他们在信息存储技术、学术或政府领域的各种职业做好准备。在十年内，金属磁性多层材料中的巨磁电阻（GMR）已经从实验室发现发展到实际应用于商业设备，如计算机中的硬盘驱动器。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是多层GMR，用垂直于各层的电流测量，这是由密歇根州立大学的研究小组首创的一种几何结构。这种几何结构保证在较小的样品中具有较大的磁阻。但根本问题和实际问题仍有待解决。该提案以新颖的方式解决了几个这样的问题。该研究项目为本科生和研究生提供了使用最先进仪器进行研究的机会，这将为他们在研究或技术领域，特别是信息存储技术领域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.***