Gate controlled anomalous phase shift in Al/InAs Josephson junctions
Gate controlled anomalous phase shift in Al/InAs Josephson junctions
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DOI：
10.1038/s41467-019-14094-1
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发表时间：
2020-01-10
影响因子：
16.6
通讯作者：
Shabani, Javad
中科院分区：
文献类型：
--
作者：
Mayer, William;Dartiailh, Matthieu C.;Shabani, Javad
在标准约瑟夫森结中，当超导引线之间的相位差为零时，电流为零。这个条件受到宇称和时间反演对称性的保护。然而，自旋-轨道耦合和磁场的组合存在打破了这些对称性，即使相位差为零，也可以导致有限的超电流。这就是所谓的反常约瑟夫森效应--超导自旋电子学的标志性效应--它可以用相应的反常相移来表征。本文报道了用超导量子干涉仪在InAs/Al约瑟夫森结中观测到的可调反常约瑟夫森效应。通过门控InAs的密度，我们能够调整约瑟夫森结中的自旋-轨道耦合。这使我们有能力调整反常相位，并为超导自旋电子学开辟了新的机会，以及实现和表征拓扑超导性的新可能性。
In a standard Josephson junction the current is zero when the phase difference between superconducting leads is zero. This condition is protected by parity and time-reversal symmetries. However, the combined presence of spin-orbit coupling and magnetic field breaks these symmetries and can lead to a finite supercurrent even when the phase difference is zero. This is the so called anomalous Josephson effect-the hallmark effect of superconducting spintronics-which can be characterized by the corresponding anomalous phase shift. Here we report the observation of a tunable anomalous Josephson effect in InAs/Al Josephson junctions measured via a superconducting quantum interference device. By gate controlling the density of InAs, we are able to tune the spin-orbit coupling in the Josephson junction. This gives us the ability to tune the anomalous phase, and opens new opportunities for superconducting spintronics, and new possibilities for realizing and characterizing topological superconductivity.