论文标题
直接电流约瑟夫森二极管的对称约束
Symmetry Constraints on Direct-Current Josephson Diodes
论文作者
论文摘要
有必要打破时间逆转和平等对称性，以实现约瑟夫森（Josephson）或超导二极管，表现出非临界临界直流电（DC）。实际上，这些条件仍然不足。自由能对整个连接场和磁场的相位差的依赖性分别分类，分别表现出电流回流（JR），场逆转和场电流的转换条件。要表现出DC Josephson二极管效应，所有满足JR条件的对称性都需要破坏。相对于磁场的临界电流的关系分为五个类，包括三个表现出二极管效应。这些对称考虑因素应用于具体的例子。我们的工作表明，DC Josephson二极管效应是JR对称性破坏的自然结果，因此提供了一种指导原理来理解或设计DC Josephson Diode。
It is necessary to break both time-reversal and parity symmetries to realize a Josephson, or superconducting, diode exhibiting nonreciprocal critical direct-currents (DC). In fact, these conditions are still insufficient. The dependencies of the free energy on the phase difference across the junction and the magnetic field are classified, exhibiting the current-reversion (JR), field-reversion, and field-current reversion conditions, respectively. To exhibit the DC Josephson diode effect, all symmetries satisfying the JR condition need to be broken. The relations of critical currents with respect to the magnetic field are classified into five classes, including three exhibiting the diode effect. These symmetry considerations are applied to concrete examples. Our work reveals that the DC Josephson diode effect is a natural consequence of the JR symmetry breaking, hence, providing a guiding principle to understand or design a DC Josephson diode.
