Self induced oscillations in non-linearly coupled magnetomechanical systems

Backaction effects in optomechanical systems can be exploited to efficiently cool thermally excited mechanical states towards their ground state . However, within specific operational regimes, the resulting backaction can give rise to a negative damping rate, consequently leading to heating of the mechanical mode and subsequently to a break-down of the linear theory. The interplay of nonlinear effects and dissipation can lead to self induced oscillations with a fixed amplitude.

Our current study focuses on the theoretical modeling of a nonlinear magnetomechanical system that exhibits self-induced oscillations. In such inductively-coupled electromechanical systems, the interaction between the mechanical mode and the microwave cavity mode is effectively mediated via a SQUID loop, thus the nonlinear aspect of the system is strongly enhanced as the cavity mode is itself nonlinear. We compare our theoretical predictions with experimental data.