Anomalous Gilbert damping and Duffing features of the superconductor-ferromagnet-superconductor φ0 Josephson junction

We study the phase dynamics, IV characteristics, and magnetization dynamics of the phi(0) Josephson junction at small values of spin-orbit interaction, ratio of the Josephson junction to magnetic energy, and Gilbert damping. We demonstrate that the coupled Landau-Lifshitz-Gilbert-Josephson dynamics is reduced to a scalar nonlinear Duffing oscillator. The resulting Duffing equation incorporates the Gilbert damping in a special way across the dissipative term and the restoring force. An anomalous shift of the ferromagnetic resonance frequency with decreasing Gilbert damping is found. We demonstrate that there is a critical damping value at which nonlinearity comes into play, and it changes the damping dependence of the ferromagnetic resonance.

Automated summary

We study the phase dynamics, IV characteristics, and magnetization dynamics of the phi(0) Josephson junction at small values of spin-orbit interaction, ratio of the Josephson junction to magnetic energy, and Gilbert damping. We demonstrate that the coupled Landau-Lifshitz-Gilbert-Josephson dynamics can be reduced to a scalar nonlinear Duffing oscillator. An anomalous shift of the ferromagnetic resonance frequency with decreasing Gilbert damping is found. There is a critical damping value at which nonlinearity comes into play and changes the damping dependence of the ferromagnetic resonance.