论文标题
浮雕拓扑超导体之间的连接处的约瑟夫森效应异常的效应和纠正
Anomalous Josephson effect and rectification in junctions between Floquet topological superconductors
论文作者
论文摘要
已知以定期驱动的基塔夫连锁店展示了新颖的浮标Majorana fermions和异常的Floquet End模式。 “浮标系统中的quasienergy”是周期性的事实，在定义定期驱动的系统中定义基态很难。为了克服这个问题，我们从非鉴定基塔夫链的基态开始，然后逐渐在时间尺度$τ$上定期开启化学电位的定期驾驶。驾驶时，非发射系统的单个粒子本征状分布在浮子状态之间的程度可以以反参与率为特征。在两个定期驱动的基塔夫链之间的约瑟夫森连接中，对阶段的阶段没有差异，而是驾驶电势阶段的不同，净平均电流从一个超导体流向另一个超导体。我们称这样的电流异常电流。此外，我们研究了两个定期驱动的超导体之间连接的当前相位关系，并发现该系统表现出无序的Josephson二极管效应。每当目前对异常电流和二极管效应做出重大贡献时，浮子Majoraga末端模式和异常的浮子末端模式。此外，当定期驾驶绝热地打开时，异常电流和非平衡的约瑟夫森二极管效应生存。
Periodically driven Kitaev chains are known to exhibit novel Floquet Majorana fermions and anomalous Floquet end modes. The fact that `quasienergy in Floquet systems is periodic' poses a difficulty in defining the ground state in periodically driven systems. To overcome this problem, we start with the ground state of the undriven Kitaev chain and gradually switch on the periodic driving in chemical potential over a timescale $τ$. The extent to which the single particle eigenstates of the undriven system get distributed among the Floquet states upon driving can be characterized by inverse participation ratio. In a Josephson junction between two periodically driven Kitaev chains not differing in phase of the pair potentials but differing in phases of the driving potentials, a net average current flows from one superconductor to the other. We term such a current anomalous current. Further, we study current phase relation in junctions between two periodically driven superconductors and find that the system exhibits nonequilibrium Josephson diode effect. The Floquet Majorana end modes and anomalous Floquet end modes whenever present contribute significantly to the anomalous current and the diode effect. Further, the anomalous current and the nonequilibrium Josephson diode effect survive when the periodic driving is adiabatically switched on.
