We present simultaneous measurements of Josephson inductance and dc transport characteristics of ballistic Josephson junctions based upon an epitaxial Al-InAs heterostructure. The Josephson inductance at finite current bias directly reveals the current-phase relation. The proximity-induced gap, the critical current and the average value of the transparency $\overline{\tau }$ are extracted without need for phase bias, demonstrating, e.g., a near-unity value of $\overline{\tau }=0.94$. Our method allows us to probe the devices deeply in the nondissipative regime, where ordinary transport measurements are featureless. In perpendicular magnetic field the junctions show a nearly perfect Fraunhofer pattern of the critical current, which is insensitive to the value of $\overline{\tau }$. In contrast, the signature of supercurrent interference in the inductance turns out to be extremely sensitive to $\overline{\tau }$.

中文翻译：

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约瑟夫森电感作为高度弹道半导体-超导体弱链接的探针

我们提出了基于外延Al-InAs异质结构的弹道约瑟夫逊结的约瑟夫森电感和直流输运特性的同步测量。有限电流偏置下的约瑟夫森电感直接揭示了电流-相位关系。接近感应间隙，临界电流和透明度的平均值$\overline{\tau }$ 无需相位偏置即可提取，这表明，例如， $\overline{\tau }=0.94$。我们的方法使我们能够在非耗散状态下对设备进行深入探测，而普通的传输测量没有任何特征。在垂直磁场中，结点显示出临界电流的近乎完美的弗劳恩霍夫模式，该模式对临界值不敏感。$\overline{\tau }$。相比之下，电感中的超电流干扰信号对$\overline{\tau }$。