Collaborative Research: Imaging of Vortex Phases in Artificially Structured Superconductors

这个合作的实验凝聚态物理项目探索了超导体中空间调制态的静态和动态相的基本物理。重点研究了这一领域中的两个重要问题：强磁场对量子隧道现象的作用，以及在人工约束几何条件下超导体中磁场诱导缺陷的动力学行为。这项工作的重点之一是使用扫描霍尔探针显微镜对调制超导态进行直接空间成像，这是一种允许对超导和磁结构上方的局部磁场进行非侵入性测绘的技术。这个项目是一项合作努力，涉及两名在磁性和超导方面具有互补专业知识的研究人员。该项目的核心部分是对研究生和本科生进行物理和材料研究技术方面的培训。他们将发展的技能将使他们在未来的各种职业道路上为国家的科学基础做出贡献。这个项目将研究超导领域的两个重要问题。在整个项目中使用的一项关键技术是扫描霍尔探针显微镜，它允许对超导和磁性结构上方的局部磁场进行非侵入性测绘。在第一个研究中，将研究强磁场在两个超导体之间电子隧穿中的作用。目前，人们对大片油田中这种隧道效应的物理机制只有部分了解。霍尔显微镜在这项研究中将是一个特别强大的工具，因为它允许对流动的超电流进行直接成像。在第二个研究领域，霍尔显微镜将被用来成像已经使用微米和纳米光刻技术构建的超导体中涡旋的静态和动态行为。要研究的一个这样的例子是一种新型的“涡旋棘轮”，在这种棘轮中，涡旋可以精确地控制移动。这种棘轮在高精度计量中可能有应用。该项目的核心部分是对研究生和本科生进行物理和材料研究技术方面的培训。他们将发展的技能将使他们在未来的各种职业道路上为国家的科学基础做出贡献。

This collaborative experimental condensed matter physics project explores the fundamental physics of static and dynamic phases of spatially modulated states in superconductors. The focus is on two important problems in this area: the role of strong magnetic fields on quantum tunneling phenomena, and the dynamic behavior of magnetic field-induced defects in superconductors in artificially constrained geometries. One emphasis of the work is on direct spatial imaging of modulated superconducting states using scanning Hall probe microscopy, a technique that allows non-invasive mapping of the local magnetic field above superconducting and magnetic structures. This project is a collaborative effort involving two investigators with complementary expertise in magnetism and superconductivity. A central part of the project is the training of both graduate and undergraduate students in physics and materials research techniques. The skills they will develop will position them to contribute to the nation's scientific base in a variety of future career paths.This project will investigate two important problems in the field of superconductivity. A key technique used throughout the project is that of scanning Hall probe microscopy, which allows non-invasive mapping of the local magnetic field above superconducting and magnetic structures. In the first study, the role of strong magnetic fields on the tunneling of electrons between two superconductors will be investigated. The physics of this tunneling in large fields is currently only partly understood. The Hall microscope will be particularly a powerful tool in this study, as it allows for the direct imaging of the flowing supercurrents. In the second area of investigation, the Hall microscope will be used to image the static and dynamic behavior of vortices in superconductors that have been structured using micro- and nano-lithographic techniques. One such example to be studied is a novel "vortex ratchet", in which vortices can be moved in precisely controlled steps. This ratchet may have possible applications in high-precision metrology. A central part of the project is the training of both graduate and undergraduate students in physics and materials research techniques. The skills they will develop will position them to contribute to the nation's scientific base in a variety of future career paths.