Abstract

The main parameters of the tunnel barrier of Josephson Nb/AlO_x/Nb and Nb/AlN/Nb junctions are estimated in a wide range of the current density using the Simmons method. The dependences of the tunnel barrier height and width of the resistivity are determined experimentally for each type of the junctions. A decrease in the tunnel barrier height of the junction with the AlN interlayer by 0.3 eV as compared to an oxide junction enables us to obtain the junctions with a current density higher than 15 kA/cm² at an insulating layer thickness of 10 Å allowable technologically, which gives the possibility to obtain quality parameter R_j/R_n no lower than 25.

中文翻译：

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超导铌基结构隧道势垒参数

摘要

使用西蒙斯方法在很宽的电流密度范围内估算了约瑟夫森Nb / AlO _x / Nb和Nb / AlN / Nb结的隧道势垒的主要参数。对于每种类型的结，通过实验确定隧道势垒高度和电阻率宽度的相关性。与氧化物结相比，与AlN中间层的结的隧道势垒高度降低0.3 eV，使我们能够在10A的绝缘层厚度下获得电流密度高于15 kA / cm ²的结，这样就有可能获得不低于25的质量参数R _j / R _n。