论文标题
AC和DC超电流二极管效应的符号逆转以及弹道式约瑟夫森交界处的0- $π$的过渡
Sign reversal of the AC and DC supercurrent diode effect and 0-$π$-like transitions in ballistic Josephson junctions
论文作者
论文摘要
最近发现的内在超电流二极管效应及其在各种系统中的及时观察结果表明，当空间和时间截止对称性都被打破时，非偏流超电流自然出现。在约瑟夫森连接中，可以用自旋切割的Andreev态来方便地描述非肾上腺的超级流。在这里，我们在其AC和DC表现中都证明了超流二极管效应的符号逆转。特别是，AC二极管效应 - 即约瑟夫森电感随着超电流的函数的不对称性 - 使我们能够在平衡附近探测电流相关关系。然后，使用最小的理论模型，我们可以将AC二极管效应的符号逆转链接到所谓的0- $π$样过渡，这是多通道连接的预测但仍然难以捉摸的功能。我们的结果证明了电感测量的潜力，这是对非常规Josephson连接的基本特性的敏感探针。
The recent discovery of intrinsic supercurrent diode effect, and its prompt observation in a rich variety of systems, has shown that nonreciprocal supercurrents naturally emerge when both space- and time-inversion symmetries are broken. In Josephson junctions, nonreciprocal supercurrent can be conveniently described in terms of spin-split Andreev states. Here, we demonstrate a sign reversal of the supercurrent diode effect, in both its AC and DC manifestations. In particular, the AC diode effect -- i.e., the asymmetry of the Josephson inductance as a function of the supercurrent -- allows us to probe the current-phase relation near equilibrium. Using a minimal theoretical model, we can then link the sign reversal of the AC diode effect to the so-called 0-$π$-like transition, a predicted, but still elusive feature of multi-channel junctions. Our results demonstrate the potential of inductance measurements as sensitive probes of the fundamental properties of unconventional Josephson junctions.
