Magneto-Electrodynamics of High Temperature Superconductors

9705129 DREW这项实验研究是关于第二类超导体的红外和微波磁光性质，重点是在正常和超导状态下的铜酸盐。使用随频率和温度变化的圆极化辐射测量超导薄膜的磁传输，然后进行Kramers-Kronig分析，将确定全复频率相关的磁电导张量。最近发现的这些数据中的特征与涡钉扎有关；混合涡钉扎/回旋共振、混合涡钉扎/涡核共振以及低频去钉扎损失带将是实验工作的重点。我们将研究离子注入对涡旋钉扎特性的影响。其他主题包括研究约瑟夫森等离子体，以及超导圆盘阵列的等离子体和磁等离子体模式。这些研究是新颖的，将提供关于高温超导的新信息，并有可能为超导科学和技术开辟新的道路。这个实验研究项目利用精密的光学测量来阐明磁场与铜酸盐(高T_c)超导体的相互作用。这些超导体具有在电机和发电机中应用的潜力，在电机和发电机中，无损耗的导电和潜在的高水平磁场可能导致更小、更轻和更高效的电机和发电机。由于铜酸盐材料内部磁力线的生热运动，这种潜力到目前为止还没有得到充分的开发。这类动议以及如何通过采用辐射或其他方式引入“钉住分位数”来减少这些动议，是需要澄清的专题之一。因此，这项实验拨款可能有助于开发改进的电气技术。这项研究的结果可能包括不同寻常的新效应或结构，可能会在技术上得到应用。这项研究项目本质上是跨学科的，涉及将接受良好培训以进入工业、政府或教育职位的研究生。***本实验研究的是II型超导体的红外和微波磁光特性。重点是正常状态和超导状态下的铜酸盐。使用随频率和温度变化的圆极化辐射测量超导薄膜的磁传输，然后进行Kramers-Kronig分析，将确定全复频率相关的磁电导张量。最近发现的这些数据中的特征与涡钉扎有关；混合涡钉扎/回旋共振、混合涡钉扎/涡核共振以及低频去钉扎损失带将是实验工作的重点。我们将研究离子注入对涡旋钉扎特性的影响。其他主题包括研究约瑟夫森等离子体，以及超导圆盘阵列的等离子体和磁等离子体模式。这些研究是新颖的，将为高温超导提供新的信息，并有可能为超导科学和技术开辟新的道路。这个实验研究项目利用精密的光学测量来阐明磁场与铜酸盐(高T_c)超导体的相互作用。这些超导体具有在电机和发电机中应用的潜力，在电机和发电机中，无损耗的导电和潜在的高水平磁场可能导致更小、更轻和更高效的电机和发电机。由于铜酸盐材料内部磁力线的生热运动，这种潜力到目前为止还没有得到充分的开发。这样的运动，以及如何通过引入辐射或其他方式的“钉扎中心”来减少它们，是需要澄清的主题之一。因此，这项实验拨款可能有助于开发改进的电气技术。这项研究的结果可能包括不同寻常的新效应或结构，可能会在技术上得到应用。这项研究项目本质上是跨学科的，涉及将接受良好培训以进入工业、政府或教育职位的研究生。***

w:\awards\awards96\num.doc 9705129 Drew This experimental research is on the infrared and microwave magneto-optical properties of Type II superconductors, with emphasis on cuprates, in both normal and superconducting states. Measurements of magneto-transmission of superconducting films using circularly polarized radiation with frequency and temperature variation, followed by kramers-Kronig analysis will determine the full complex frequency-dependent magneto- conductivity tensor. Features in such data recently discovered to be related to vortex pinning; the hybridized vortex pinning/cyclotron resonance, the hybridized vortex pinning/vortex core resonance, and the low frequency depinning loss band, will be a focus of the experimental work. The effects on these properties of vortex pinning as introduced by ion implantation will be studied. Additional topics include studies of Josephson plasmons, and of plasma and magneto-plasma modes of arrays of superconducting disks. These studies are novel and will provide new information on high temperature superconductivity, with the possibility of opening new paths for the science and technology of superconductivity. %%% This experimental research project makes use of sophisticated optical measurements to clarify the interaction of magnetic fields with cuprate (high Tc) superconductors. These superconductors have the potential for application in motors and generators, where the loss-free electrical conduction and potentially high levels of magnetic field could lead to smaller, lighter, and more efficient motors and generators. The full exploitation of this potential has not been reached thus far, because of heat generating motions of the magnetic field lines inside the cuprate material. Such motions, and how they may be reduced by introduction of "pinning cent ers" by irradiation or other means, are one of the topics to be clarified. This experimental grant may thereby help to develop an improved electrical technology. Results from this research may include unusual new effects or structures which may find 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. *** This experimental research is on the infrared and microwave magneto-optical properties of Type II superconductors, with emphasis on cuprates, in both normal and superconducting states. Measurements of magneto-transmission of superconducting films using circularly polarized radiation with frequency and temperature variation, followed by Kramers-Kronig analysis will determine the full complex frequency-dependent magneto- conductivity tensor. Features in such data recently discovered to be related to vortex pinning; the hybridized vortex pinning/cyclotron resonance, the hybridized vortex pinning/vortex core resonance, and the low frequency depinning loss band, will be a focus of the experimental work. The effects on these properties of vortex pinning as introduced by ion implantation will be studied. Additional topics include studies of Josephson plasmons, and of plasma and magneto-plasma modes of arrays of superconducting disks. These studies are novel and will provide new information on high temperature su perconductivity, with the possibility of opening new paths for the science and technology of superconductivity. %%% This experimental research project makes use of sophisticated optical measurements to clarify the interaction of magnetic fields with cuprate (high Tc) superconductors. These superconductors have the potential for application in motors and generators, where the loss-free electrical conduction and potentially high levels of magnetic field could lead to smaller, lighter, and more efficient motors and generators. The full exploitation of this potential has not been reached thus far, because of heat generating motions of the magnetic field lines inside the cuprate material. Such motions, and how they may be reduced by introduction of "pinning centers" by irrradiation or other means, are one of the topics to be clarified. This experimental grant may thereby help to develop an improved electrical technology. Results from this research may include unusual new effects or structures which may find 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. ***