Scanning Hall Probe Microscopy of Superconducting Systems

超导系统的扫描霍尔探针显微镜

• 批准号: 9701532
• 负责人: Stuart Field
• 金额: $ 26.95万
• 依托单位: Colorado State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-08-15 至 2002-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9701532&HistoricalAwards=false
• 关键词: Scanning; Hall; Probe; Microscopy; Superconducting

w:\awards\awards96\num.doc 9701532 Field This experimental research project focuses on unusual magnetic properties of Type II superconductors using a state of the art cryogenic scanning Hall probe microscope, with high spatial (one micrometer) and temporal resolutions. The first system to be studied is a large array of mesoscopic superconducting rings. The magnetic moments in such rings can couple "antiferromagnetically", via purely magnetic interactions, which have been observed in preliminary experiments. Cleaner arrays will be studied in a search for true long range order. The microscope will also be used to study the static and dynamic properties of vortices in superconductors with both random and periodic pinning. In the random case the primary interest is in spatially-resolved dynamics of vortices in a disordered potential, when strongly driven by either magnetic fields or applied currents, with the expectation of getting new information on the depinning transition. With periodic pinning, experiments will probe the consequences of variations of two competing length scales: the vortex-vortex spacing and the distance between pinning sites. %%% This experimental research project explores the magnetic properties of superconductors, with particular attention to how magnetic flux moves through a superconductur when pushed by an external magnetic field, or by a current passing through the superconductor. Since it is this flux motion which generally results in the loss of perfect conductivity, which is the hallmark of superconductors, a deeper understanding of these issues may lead to improved technological applications of superconductors, as in power generation and transmission. The flux motion will be imaged using the powerful new technique of scanning Hall probe microscopy. The further deve lopment of this instrument, which may find use in many fields (such as hard disk technologies) where the local structure of the magnetic field is of interest, is an integral part of the project. Results from this research may include unusual new effects or materials which may find new application in technology. This research project is interdisciplinary in nature and involves graduate students who will be excellently trained to enter positions in industry, government or education. ***

w:\awards\awards96\num.doc 9701532 领域 该实验研究项目的重点是使用最先进的低温扫描霍尔探针显微镜，具有高空间（一微米）和时间分辨率，研究 II 型超导体的异常磁特性。第一个要研究的系统是大型介观超导环阵列。这种环中的磁矩可以通过纯磁相互作用进行“反铁磁”耦合，这已在初步实验中观察到。 将研究更干净的数组以寻找真正的长程顺序。 该显微镜还将用于研究具有随机和周期性钉扎的超导体中涡流的静态和动态特性。在随机情况下，主要兴趣在于无序势中涡旋的空间分辨动力学，当受到磁场或施加电流的强烈驱动时，期望获得有关脱钉转变的新信息。 通过周期性钉扎，实验将探讨两个相互竞争的长度尺度变化的后果：涡旋-涡旋间距和钉扎位点之间的距离。 %%% 该实验研究项目探索超导体的磁性，特别关注当外部磁场或通过超导体的电流推动时，磁通量如何穿过超导体。 由于这种通量运动通常会导致失去完美的导电性，而这是超导体的标志，因此对这些问题的更深入了解可能会导致超导体技术应用的改进，例如在发电和传输方面。 将使用强大的扫描霍尔探针显微镜新技术对通量运动进行成像。该仪器的进一步开发可能会在许多对磁场局部结构感兴趣的领域（例如硬盘技术）中得到应用，这是该项目的一个组成部分。 这项研究的结果可能包括不寻常的新效应或可能在技术中找到新应用的材料。该研究项目本质上是跨学科的，涉及研究生，他们将接受良好的培训，以进入工业、政府或教育部门。 ***