论文标题
旋转波近似以外的约瑟夫森参数下转换导致的周期三倍
Period tripling due to Josephson parametric down-conversion beyond the rotating-wave approximation
论文作者
论文摘要
参数驱动的振荡器可以以三次谐振频率响应驱动器显示周期转移。与周期加倍的参数不稳定性相反，与静止状态相对应的对称的固定点在三胞胎过渡的任意强驾驶时保持稳定。以前，已经表明，波动可以绕过这一点并引起周期性的不稳定。在本文中，我们探讨了一种替代方法，该方法是通过研究旋转波近似之外的参数下转换而引起的周期转移的特性来诱导周期陷阱过渡。我们表明，尽管没有不稳定性阈值，但非谐振频率贡献可以通过激活参数下转换来诱导周期转移的转变。此外，我们研究了约瑟夫森电位的随后的周期三级状态，并讨论了仅在旋转波近似之外出现的顺时针和逆时针旋转固定点之间的不对称性。
Parametrically driven oscillators can display period-tripling in response to a drive at thrice the resonance frequency. In contrast to the parametric instability for period doubling, the symmetric fixed-point corresponding to the state of rest remains stable at arbitrary strong driving for the tripling transition. Previously, it has been shown that fluctuations can circumvent this and induce a period-tripling instability. In this article, we explore an alternative way of inducing a period-tripling transition by investigating properties of period-tripling due to parametric down-conversion beyond the rotating-wave approximation. We show that despite the absence of an instability threshold, off-resonant frequency contributions can induce a period-tripling transition by activating the parametric down-conversion. Moreover, we study the subsequent period-tripled states of the Josephson potential and discuss the asymmetry between the clockwise and counter-clockwise rotating fixed-points that only arises beyond the rotating-wave approximation.
