论文标题
可敲门的约瑟夫森二极管
The gate-tunable Josephson diode
论文作者
论文摘要
超导二极管是最近发现的经典二极管的量子类似物。超导二极管效应依赖于时间反转和反转对称性的破坏。结果,超导体的临界电流可以取决于所施加电流的方向。这些成分的组合自然发生在磁场下的接近半导体中,这也预计会引起外来物理,例如拓扑超导性。在这项工作中,我们使用AL邻近的INSB纳米线来研究超导二极管效应。通过阴影墙光刻,我们创建了短的约瑟夫森连接,并通过半导体弱环和近端的导线进行门控制。当磁场垂直于纳米线轴时,超导二极管效应取决于平面外角。特别是,它沿特定角度是最强的,我们将其解释为近端铅中自旋轨道场的方向。此外,静电门可用于极大地改变这种效果,甚至完全抑制它。最后,当磁场平行于纳米线轴时,我们还观察到明显的栅极可调二极管效应。由于通过静电门控具有相当大的控制程度,半导体 - 驱动器混合动力约瑟夫森二极管(Josephson Diode)成为创新超导电路和计算设备的有希望的元素。
Superconducting diodes are a recently-discovered quantum analogueue of classical diodes. The superconducting diode effect relies on the breaking of both time-reversal and inversion symmetry. As a result, the critical current of a superconductor can become dependent on the direction of the applied current. The combination of these ingredients naturally occurs in proximitized semiconductors under a magnetic field, which is also predicted to give rise to exotic physics such as topological superconductivity. In this work, we use InSb nanowires proximitized by Al to investigate the superconducting diode effect. Through shadow-wall lithography, we create short Josephson junctions with gate control of both the semiconducting weak link as well as the proximitized leads. When the magnetic field is applied perpendicular to the nanowire axis, the superconducting diode effect depends on the out-of-plane angle. In particular, it is strongest along a specific angle, which we interpret as the direction of the spin-orbit field in the proximitized leads. Moreover, the electrostatic gates can be used to drastically alter this effect and even completely suppress it. Finally, we also observe a significant gate-tunable diode effect when the magnetic field is applied parallel to the nanowire axis. Due to the considerable degree of control via electrostatic gating, the semiconductor-superconductor hybrid Josephson diode emerges as a promising element for innovative superconducting circuits and computation devices.