Theoretical Studies of Josephson Arrays, High-Temperature Superconductors, and Inhomogeneous Media

约瑟夫森阵列、高温超导体和非均匀介质的理论研究

• 批准号: 0104987
• 负责人: David Stroud
• 金额: --
• 依托单位: Ohio State University Research Foundation -DO NOT USE
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-07-01 至 2004-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0104987&HistoricalAwards=false
• 关键词: Theoretical; Studies; Josephson; Arrays; Temperature

0104987StroudTheoretical research will be conducted in three areas of materials research: (1) the physics of superconducting arrays and related materials: (2) fluctuations and inhomogeneities in cuprate-based high temperature superconductors; (3) linear and nonlinear response of macroscopically inhomogeneous materials. Superconducting arrays are arrangements of superconductors which are weakly coupled together by Josephson or proximity-effect interactions. They have a wide variety of potential applications and are also good models for superconducting thin films. In this area continued study of underdamped Josephson arrays coupled to a resonant cavity will be carried out. In addition, a study of noise produced by magnetic flux motion in arrays and films will also be undertaken, as well as a study of conditions under which a superconducting array can lock into a coherent state. Finally, a study will be made of quantum effects in superconducting arrays, films and smaller groups of junctions. Models for terahertz absorption in the underdoped high temperature superconducting materials will be studied. Also to be investigated are models of low-angle grain boundaries in the ab-planes of the high temperature superconductors, since grain boundaries limit the critical current. The c-axis current-voltage characteristics of these materials will also be investigated, as well as the conditions governing the position and width of the Josephson plasmon resonance in the most anisotropic materials. Also, recent calculations o fquantum melting of the vortex lattice at zero temperature will be compared to experiment. The PI will also extend recent work on macroscopically inhomogeneous media to the study of magnetic composites. Here the problems to be addressed include magnetoresistance arising from the inhomogeneous conductivity tensor in a material with a ferromagnetic domain structure, and the behavior of magnetic multilayers coupled through nonmagnetic layers, which will be studied by a model analogous to the Lawrence-Doniach treatment of layered superconductors. Finally, the PI will study the electromagnetic response of collections of small metal and dielectric particles contained in an optical microcavity.The research involves studies of several fundamental questions in condensed matter physics, and may lead to a wide variety of technological applications. It will also contribute to human resources in science and technology by training graduate students and postdoctoral fellows.%%%Theoretical research will be conducted in three areas of materials research: (1) the physics of superconducting arrays and related materials: (2) fluctuations and inhomogeneities in cuprate-based high temperature superconductors; (3) linear and nonlinear response of macroscopically inhomogeneous materials. The research involves studies of several fundamental questions in condensed matter physics, and may lead to a wide variety of technological applications. It will also contribute to human resources in science and technology by training graduate students and postdoctoral fellows.***

0104987斯特劳德理论研究将在材料研究的三个领域进行：（1）超导阵列和相关材料的物理学;（2）铜基高温超导体中的波动和不均匀性;（3）宏观不均匀材料的线性和非线性响应。 超导阵列是超导体的排列，它们通过约瑟夫森或邻近效应相互作用弱耦合在一起。 它们具有广泛的潜在应用，也是超导薄膜的良好模型。 在这一领域，将继续研究耦合到谐振腔的欠阻尼约瑟夫森阵列。 此外，还将对阵列和薄膜中磁通量运动产生的噪声进行研究，并对超导阵列能够锁定到相干状态的条件进行研究。 最后，将研究超导阵列、薄膜和更小的结群中的量子效应。 研究欠掺杂高温超导材料的太赫兹吸收模型。 由于晶界限制了临界电流，因此还将研究高温超导体ab平面中的小角度晶界模型。 这些材料的c轴电流-电压特性也将被研究，以及在最各向异性的材料中的约瑟夫森等离子体共振的位置和宽度的条件。 此外，最近的计算fquantum熔化的涡旋晶格在零温度下将与实验进行比较。PI还将扩展最近的工作宏观不均匀介质的磁性复合材料的研究。 在这里要解决的问题包括磁阻所产生的不均匀的电导率张量的材料与铁磁畴结构，和磁性多层膜的行为耦合通过介电层，这将被研究的模型类似于劳伦斯-多尼亚克处理层状超导体。 最后，PI将研究包含在光学微腔中的小金属和电介质颗粒的电磁响应。该研究涉及凝聚态物理学中的几个基本问题的研究，并可能导致各种各样的技术应用。 它还将通过培训研究生和博士后研究员，为科学和技术人力资源做出贡献。理论研究将在材料研究的三个领域进行：（1）超导阵列和相关材料的物理学;（2）铜基高温超导体中的波动和不均匀性;（3）宏观不均匀材料的线性和非线性响应。 该研究涉及凝聚态物理学中几个基本问题的研究，并可能带来广泛的技术应用。 它还将通过培训研究生和博士后研究员，为科技人力资源作出贡献。