Title: Perfect supercurrent diode efficiency in chiral nanotube-based Josephson junctions Show Chinese title

Title: 手性纳米管基约瑟夫森结中的完美超电流二极管效率

Abstract: The supercurrent diode effect (SDE) describes superconducting systems where the magnitude of the superconducting-to-normal state switching current differs for positive and negative current bias. Despite the ubiquity of such diode effects in Josephson devices, the fundamental conditions to observe a diode effect in a Josephson junction and achieve perfect diode efficiency remain unclear. In this work, we analyze the supercurrent diode properties of a chiral nanotube-based Josephson junction within a Ginzburg-Landau theory. We find a diode effect and anomalous phase develops across the junction when a magnetic field is applied parallel to the tube despite the absence of spin-orbit interactions in the system. Unexpectedly, the SDE in the junction is independent of the anomalous phase. Alternatively, we determine a non-reciprocal persistent current that is protected by fluxoid quantization can activate SDE, even in the absence of higher-order pair tunneling processes. We show this new type of SDE can lead to, in principle, a perfect diode efficiency, highlighting how persistent currents can be used to engineer high efficiency supercurrent diodes. Show Chinese abstract

Abstract: 超电流二极管效应（SDE）描述了超导系统中，在正向和负向电流偏置下，超导态到正常态转换电流的大小不同的情况。 尽管约瑟夫森器件中存在这种二极管效应的普遍性，但观察到约瑟夫森结中的二极管效应以及实现完美二极管效率的基本条件仍不清楚。 在这项工作中，我们基于Ginzburg-Landau理论分析了基于手性纳米管的约瑟夫森结的超电流二极管特性。 我们发现，当磁场平行于纳米管施加时，尽管系统中不存在自旋-轨道相互作用，但在结处会发展出二极管效应和异常相位。 出乎意料的是，结中的SDE与异常相位无关。 或者，我们确定了一种非互易的持续电流，它受到磁通量子化的保护，可以在甚至没有高阶配对隧穿过程的情况下激活SDE。 我们展示了这种新型的SDE原则上可以导致完美的二极管效率，强调了如何利用持续电流来设计高效超电流二极管。