Multilayer Josephson Junction Digital Devices

9500279 Lommatch这笔赠款的目标是研究传统和新型超导数字磁通量子器件，该器件采用相对较新的技术，即具有n层超导-绝缘体(SI)层的多层约瑟夫森结。这项工作涉及对多层结和器件行为的广泛的数值模拟。该计划将借鉴以前的计算和实验研究的结果，这些研究是在美国国家科学基金会研究计划拨款所涵盖的时期进行的。拟议研究的主要重点将是磁通量子电路的数值模拟，其中多层结既用作非线性动力学电感(无源器件)以增加电路集成密度，又用作单三层结替代(有源器件)以允许新的逻辑/电压阈值、新颖的器件设计、器件容错和抗热噪声。我们的目标将是优化电路设计，以最大限度地提高参数变化容差，并包括实际考虑因素，如串扰和寄生电容和电感，以便生产适合于制造测试原型的光刻掩模。传统的数字器件，如选择逻辑和存储电路，将被考虑以获得最佳的几何形状和性能。由于本地存储和处理的自然集成，通量量子电路所提供的独特的操作特性被多层结技术进一步利用，因此将分析几种新的器件，特别是在基于神经的计算和半导体接口领域。如果超导数字电路要达到其低功耗所允许的集成密度，并且如果它要在不止几个小众应用中与室温半导体数字电路竞争，那么必须进行像这里提出的这样的工作。***

9500279 Lomatch The objectives of this grant are to study conventional and novel superconducting digital flux quantum devices employing the relatively young technology of multilayer Josephson junctions with n superconductor-insulator (SI) layers. The work involves the extensive numerical modeling of multilayer junction and device behavior. This program will draw from the results of previous computational and experimental studies, which took place during the period covered by an NSF Research Planning Grant. A primary focus of the proposed research will be the numerical simulation of flux quantum circuitry in which multilayer junctions both serve as nonlinear kinetic inductors (passive devices) to increase circuit integration density, and as single trilayer junction replacements (active devices) to allow for new logic/voltage thresholds, novel device designs, device fault tolerance, and resistance to thermal noise. The goal will be to optimize circuit designs to maximize parameter variation tolerances, and to include realistic considerations such as crosstalk and parasitic capacitance's and inductances so that one may produce lithographic masks suitable for the fabrication of test prototypes. Conventional digital devices, such as select logic and memory circuitry, will be considered for optimum geometry and performance. the unique operational features offered by flux quantum circuitry due to the natural integration of local memory and processing are further exploited by multilayer junction technology, so several novel devices will be analyzed, particularly in the area of neural-based computing and semiconductor interfacing. If superconducting digital circuitry is to achieve the integration density that its low power dissipation allows, and if it is to compete with room temperature semiconducting digital circuitry in more than a few small niche applications, then work such as the proposed here must be pursued. ***