Stability of the Kink State in a Stack of Intrinsic Josephson Junctions

A new dynamic state characterized by $(2m_l+1)\pi$ static phase kink with integers $\{m_l\}$ is proposed recently in a stack of inductively coupled Josephson junctions. In the present paper, the stability of the phase kink state is investigated against many perturbations and it is shown that the kink state is stable. It is also discussed that the suppression of the amplitude of superconducting order parameter caused by the kink is weak.