Simultaneous ground state cooling of two mechanical resonators weakly coupled with three optical cavities in the unresolved sideband regime

In this study we propose ground state cooling scheme of an optomechanical system consisting of three optical cavities and two mechanical oscillators where the second cavity is linearly coupled to the other cavities and each mechanical resonator is optomechanically coupled to its respective optical cavity. We derive the optical conditions of cooling by calculating and plotting the optical force spectrum. Ground state cooling of the system is achievable in both the resonators simultaneously or in any one of them in unresolved sideband regime as the heating process can be effectively suppressed in optimal parameter values. It is also noted that the cooling process gets more efficient as more cavity modes are coupled due to addition of new interference paths. Finally the system has been numerically simulated and it is observed that the optimal conditions for cooling found in the simulation coincide with the ones derived analytically.