Improving cooling performance in an optomechanical system using a nonlinear cavity – Part 2

Ground state cooling of a mechanical resonator is the prerequisite to utilize them for quantum information processing, and for ultrasensitive precision measurements at the quantum limit. In the field of cavity optomechanics dynamical backaction cooling and feedback protocols have been successfully used to bring macroscopic mechanical elements into or near the quantum ground state. Cooling in the linear regime of optomechanics has been extensively studied in the literature. However, here we show the emergence of new effects once a nonlinear environment for the mechanics is considered. We study the cooling properties of a mechanical resonator coupled to a nonlinear cavity, acting as a high-Q Duffing oscillator. We demonstrate that the presence of the Duffing-nonlinearity improves the cooling efficiency significantly. Moreover, we show that the cooling still improves even when driving the oscillator beyond bistability. These advantages of the nonlinear environment are not limited to the resolved sideband regime, and extend the realm of optomechanical architectures in the quantum regime.