射频驱动具有平方阻尼项的Josephson结混沌起始阈值的研究

STUDY OF THE ONSET OF CHAOS IN THE RF-BIASED JOSE-PHSON JUNCTION WITH QUADRATIC DAMPING

本文将运用Melnikov方法求得的射频驱动、具有平方阻尼项的Josephson结参数空间中混沌起始阈值与数值计算结果进行对照。研究表明,Melnikov方法所预测的混沌区域仅占据很窄的射频幅值范围,且是位相锁定的混沌态,而实验观测的混沌位于较大的射频幅值,为非位相锁定的混沌。

In this paper, the rf-amplitude threshold of chaos in a Josephson junction with quadratic damping is studied. Theoretical predictions based on the method of Melnikov is compared with numerical simulations. It is shown that the chaotic region predicted by the method of Melnikov spans only a narrow region of rf-amplitude and consists of phase locked chaos. The experimentally observed threshold of chaos is shown to coincide with the onset of unlocked chaotic behavior at higher rf-amplitude.