Amorphous Nb-Si Barrier Junctions for Voltage Standard and Digital Applications
Amorphous Nb-Si Barrier Junctions for Voltage Standard and Digital Applications
复制标题
用于电压标准和数字应用的非晶铌硅势垒结
DOI：
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发表时间：
2009
影响因子：
1.8
通讯作者：
E. Grossman
中科院分区：
文献类型：
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作者：
D. Olaya;P. Dresselhaus;S. Benz;J. Bjarnason;E. Grossman
非晶Nb-Si先前已被证明是铌基超导电压标准电路的约瑟夫森结势垒材料，包括工作频率高达20 GHz的直流可编程和交流约瑟夫森电压标准。选择这种材料是为了使结可以在垂直堆叠中制造，增加阵列中结的数量，从而增加电路的输出电压。这种屏障材料也可以用于制造高速结，因为导致改进堆叠的相同因素也会导致具有薄绝缘屏障的更可复制的结。最近，德国物理技术研究所（PTB）和美国国家标准与技术研究所（NIST）合作生产了使用这些结工作在75 GHz的1v和10v可编程约瑟夫森电压标准芯片。在本文中，我们展示了特征频率接近500 GHz的结，并在400 GHz和800 GHz的频率下观察到约瑟夫森锁相。这些结有望应用于高速超导数字电子器件。
Amorphous Nb-Si has been previously demonstrated as a Josephson junction barrier material for Nb-based superconducting voltage standard circuits, including both DC programmable and AC Josephson voltage standards operating at frequencies up to 20 GHz. This material was chosen so that the junctions could be fabricated in vertical stacks, increasing the number of junctions in an array, which in turn increases the output voltage of the circuits. This barrier material may also be used to create higher-speed junctions, because the same factors that lead to improved stacks also lead to more reproducible junctions with thin, insulating barriers. Recently, a collaboration between the Physikalisch-Technische Bundesanstalt (PTB) and the National Institute of Standards and Technology (NIST) produced 1 V and 10 V programmable Josephson voltage standard chips operating at 75 GHz that use these junctions. In this paper, we demonstrate junctions with characteristic frequencies approaching 500 GHz and observed Josephson phase locking at frequencies of 400 GHz and 800 GHz. These junctions are promising for applications in high-speed superconducting digital electronics.