GOALI: Three-Dimensional Josephson Junction Arrays

这个GOALI实验研究项目涉及全新的约瑟夫森结三维阵列，它将首次使用先进的微光刻技术和设备制造。一个与相变、高温超导体模型系统和涡旋运动有关的全新行为领域将在三维阵列中实现，而不是以前研究的约瑟夫森结的二维阵列。制造新型器件阵列的步骤将包括多层沉积，康奈尔大学纳米制造设施的电子束写入和掩膜制造，以及德克萨斯州理查森的PlasmaQuest的电子回旋共振（ECR）蚀刻。在阵列的测量中，重点将放在电导率、磁化率和临界场的三维临界波动上。其他感兴趣的主题是三维XY哈密顿量的建模，三维自旋系统受挫的本质，以及相变中的2- 3维交叉效应。这项研究将涉及研究生和博士后研究人员，他们将接受良好的培训，有利于他们未来在工业、政府或学术研究领域的职业生涯。这项工作本质上是跨学科的，并得到了美国国家科学基金会数学和物理科学理事会多学科活动办公室的部分支持。该实验研究项目属于“与工业界学术联络资助机会”（GOALI）的范畴，旨在促进学术界和工业界研究人员之间的合作。这个项目是关于全新的，约瑟夫森结的三维阵列。超导电极之间的约瑟夫森结是高度非线性的器件元件，其行为受到磁场的强烈影响，即使在单个“通量量子”的水平上也是如此。由于这个原因，约瑟夫森结实际上用于灵敏的磁场探测器。约瑟夫逊结阵列是研究超导体磁通量运动和相变的模型系统。一个与相变、高温超导体模型系统和涡旋运动有关的全新行为领域将在三维阵列中实现，而不是以前研究的约瑟夫森结的二维阵列。制造新型器件阵列的步骤将包括多层沉积，康奈尔大学纳米制造设施的电子束写入和掩膜制造，以及德克萨斯州理查森的PlasmaQuest的电子回旋共振（ECR）蚀刻。由于要研究的系统是其他类型物理系统的模型，因此将获得的信息可能在其他科学分支中有价值，例如在非线性振荡器耦合可能很重要的工程中。这项研究将涉及研究生和博士后研究人员，他们将接受良好的培训，有利于他们未来在工业、政府或学术研究领域的职业生涯。这项工作本质上是跨学科的，并得到了美国国家科学基金会数学和物理科学理事会多学科活动办公室的部分支持。＊＊＊

w:\awards\awards96\*.doc 9801825 Newrock This GOALI experimental research project is concerned with entirely new, three-dimensional arrays of Josephson junctions, which will be fabricated for the first time making use of advanced microlithographic techniques and facilities. An entirely new domain of behavior relating to phase transitions, model systems for high temperature superconductors, and vortex motion will be made accessible in three dimensional arrays, rather than the previously studied two-dimensional arrays of Josephson Junctions. The steps in fabricating the novel device arrays will include the deposition of multilayers, e-beam writing and mask fabrication at the Cornell University Nanofabrication Facility, and electron cyclotron resonance (ECR) etching at PlasmaQuest in Richardson Texas. In measurements on the arrays, focus will be on three-dimensional critical fluctuations in the conductivity, the susceptibility, and the critical field. Other topics of interest are modeling the three-dimensional XY Hamiltonian, the nature of frustration in 3-d spin systems, and 2- to 3-dimensional crossover effects in the phase transition. The research will involve graduate student and postdoctoral researchers who will receive excellent training beneficial to their future careers in industry, government or academic research. This work is interdisciplinary in nature and is supported in part by the Office of Multidisciplinary Activities in the Mathematical and Physics Sciences Directorate at NSF. %%% This experimental research project is in the category of Grant Opportunities for Academic Liaison With Industry (GOALI), which fosters collaboration between academic and industrial researchers. This project is concerned with entirely new, three- dimensional arrays of Josephson junctions. Josephson junctions between superconducting electrodes are highly non-linear device elements whose behavior is strongly influenced by magnetic fields, even at the level of the single "flux quantum". For this reason Josephson Junctions are in fact used in sensitive magnetic field detectors. Arrays of Josephson Junctions are model systems for the motion of magnetic flux in superconductors and also for studying phase transitions. An entirely new domain of behavior relating to phase transitions, model systems for high temperature superconductors, and vortex motion will be made accessible in three dimensional arrays, rather than the previously studied two- dimensional arrays of Josephson Junctions. The steps in fabricating the novel device arrays will include the deposition of multilayers, e-beam writing and mask fabrication at the Cornell University Nanofabrication Facility, and electron cyclotron resonance (ECR) etching at PlasmaQuest in Richardson Texas. Because the systems to be studied are models for other types of physical systems, the information that will be obtained may be of value in other branches of science, for example in engineering where coupling of non-linear oscillators may be important. The research will involve graduate student and postdoctoral researchers who will receive excellent training beneficial to their future careers in industry, government or academic research. This work is interdisciplinary in nature and is supported in part by the Office of Multidisciplinary Activities in the Mathematical and Physics Sciences Directorate at NSF. ***