“…The first two terms in H m are the potential energy and the kinetic energy of the simple harmonic oscillator, respectively, the third term involving q 3 is the potential energy produced by the cubic mechanical nonlinearity, the parameter α is the strength of the mechanical nonlinearity. It is noted that many aspects of a cubic nonlinear oscillator have been studied, such as the behavior of the resonances [37], the quantum mechanical tunnelling [38], the Bender-Wu branch points [39], the real spectrum [40], the Stark effect [41], the periodic motion [42], and the homoclinic bifurcation [43]. Moreover, in the adiabatic limit of ω m πc/L (c is the speed of light in vacuum, L is the length of the cavity), the oscillation of the movable mirror is very slow, thus the scattering of the photons to the other cavity modes can be neglected, so there is only one cavity mode in the cavity [44].…”