Electromagnetic Imaging of Vortex Dynamics in High-Temperature Superconductors

这项个人研究者奖授予了罗切斯特大学的几位教授，他们的项目旨在提高对高温超导体（HTS）中涡流动力学和钉住效应的理解。该项目将利用现代飞秒激光技术以及电光（EO）和磁光（MO）成像方法，提供高温超导薄膜、单晶和导线中固有涡旋动力学的时间分辨二维图像。需要解决的具体问题包括随机和周期性钉钉作用下的涡旋成核和运动，输运电流诱导的涡旋物质的动态相变，以及临界电流以上通量通道中的涡旋速度分布。本研究对高温超导材料的大功率应用具有重要意义。这是一个高度跨学科的研究项目，将涉及罗切斯特大学物理、材料科学、电气和计算机工程专业的研究生和本科生以及教职员工，以及阿贡国家实验室的研究人员。学生将获得技能，使他们能够在未来的市场竞争。超导体是非常重要的，因为它们能以零电阻携带非常大的电流。这些电流反过来又产生非常大的磁场。然而，当电流超过某个“临界电流”时，材料将不再是超导体，因为磁涡流会突然穿透超导体，在材料中产生电阻损失，有时还会产生灾难性的加热。为了制造能够承载更大电流的超导体，有必要更详细地了解这种击穿机制。罗彻斯特大学的几位教授获得了这项个人研究者奖，他们的一个项目将利用飞秒激光器作为超快二维成像相机，在超导体发生击穿时拍摄一系列快照，从而拍摄出磁涡流进入超导体时快速动态的“慢动作电影”。这项研究的结果应该为制造高质量的高温超导导线、胶带和薄膜提供线索，用于各种电子和能源相关的应用。这是一个高度跨学科的研究项目，将涉及罗切斯特大学物理、材料科学、电气和计算机工程专业的研究生和本科生以及教职员工，以及阿贡国家实验室的研究人员。学生们将获得技能，使他们能够在未来的市场竞争

This individual investigator award is to several professors at the University of Rochester for a project aimed at an improved understanding of the vortex dynamics and pinning effects in high-temperature superconductors (HTS). This project will make use of modern femtosecond laser techniques and both electro-optic (EO) and magneto-optic (MO) imaging methods to provide time-resolved two-dimensional images of intrinsic vortex dynamics in HTS thin films, single crystals, and wires. Specific problems to be addressed include vortex nucleation and motion in the presence of random and periodic pinning, dynamical phase transitions of vortex matter induced by transport current, and vortex velocity distributions in flux-flow channels above the critical current. This research should have important implications for high-power applications of HTS materials. This is a highly interdisciplinary research project, which will involve graduate and undergraduate students and faculty members in physics, materials science, and electrical and computer engineering at the University of Rochester, as well as researchers at Argonne National Laboratory. The students will gain skills to enable them to compete in the future market place.%%%Superconductors are of great importance because they can carry very large electrical currents with zero resistance. These currents in turn produce very large magnetic fields. However, for currents above a certain "critical current", the material will no longer be a superconductor since magnetic vortices suddenly penetrate the superconductor, producing resistive loss and sometimes catastrophic heating in the material. In order to make superconductors that can carry ever higher currents, it is essential to understand this breakdown mechanism in more detail. This individual investigator award is to several professors at the University of Rochester for a project that will make use of femtosecond lasers arranged as ultrafast two-dimensional imaging cameras to take a series of snapshots of a superconductor while this breakdown is taking place, resulting in a "slow-motion movie" of the rapid dynamics of the magnetic vortices as they enter the superconductor. The results of this study should provide clues to making higher-quality High-temperature superconducting wires, tapes, and thin films for a variety of electronic and energy-related applications. This is a highly interdisciplinary research project, which will involve graduate and undergraduate students and faculty members in physics, materials science, and electrical and computer engineering at the University of Rochester, as well as researchers at Argonne National Laboratory. The students will gain skills to enable them to compete in the future market place.***