Overdamped niobium-nitride junctions for 10 K operation
Overdamped niobium-nitride junctions for 10 K operation
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DOI：
10.1109/77.783725
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发表时间：
1999-06
影响因子：
1.8
通讯作者：
H. Akaike;R. Oke;T. Aoyama;A. Fujimaki;H. Hayakawa
中科院分区：
文献类型：
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作者：
H. Akaike;R. Oke;T. Aoyama;A. Fujimaki;H. Hayakawa
我们制备了过阻尼的NbN/NbNx/NbN Josephson结，IcR积为0.64 mV，临界电流密度Jc为1.2 kA/cm/sup 2/。通过对超导NbN基电极表面进行等离子体氮化处理，形成NbNx屏障。虽然结在4.2 K时表现出小滞回特性，但随着温度的升高，结转变为过阻尼结。我们获得了过阻尼结，其Jc范围为0.05 kA/cm/sup 2/至3.3 kA/cm， IcR积范围为0.11 mV至0.64 mV。从Ic对温度的依赖性角度讨论了结的特性。另一方面，4.2 K时的小迟滞特性使我们能够使用一系列结来评估Ic的扩散。在4.2 K下，面积为5/spl倍/5 /spl mu/m/sup 2/的一系列64个结点的标准偏差1-4为2.9%。
We have fabricated overdamped NbN/NbNx/NbN Josephson junctions with the IcR product of 0.64 mV and the critical current density Jc of 1.2 kA/cm/sup 2/ at 10 K. The NbNx barriers are formed by plasma nitridation of the surface of the superconductive NbN base electrodes. Although the junctions show small-hysteretic characteristics at 4.2 K, they change to overdamped ones with increasing temperature. We obtained the over-damped junctions with the Jc ranging from 0.05 kA/cm/sup 2/ to 3.3 kA/cm and the IcR product ranging from 0.11 mV to 0.64 mV at 10 K. The junction characteristics are discussed from a viewpoint of the dependence of Ic on temperature. On the other hand, small hysteretic characteristics at 4.2 K enable us to evaluate Ic spread using a series of junctions. The standard deviation, 1-4 was 2.9% for a series of 64 junctions with an area of 5/spl times/5 /spl mu/m/sup 2/ at 4.2 K.