| In this paper,the properties and emission spectra of two-level atoms in a cavity optomechanical system are studied.The effects of the vibration of the moving cavity mirror on the atomic population,linear entropy and atomic emission spectrum are investigated.When the radiation pressure of the light field is acting on the movable end mirror,the end mirror vibrates,which results in the change of the length of the cavity and the spatial distribution of the intensity of the light field in the cavity,thus affecting the properties of the atom interacting with the cavity field and its emission spectrum.We first study the atomic population and linear entropy of the two-level atom.The result shows that for the initial state where the atom is prepared in its ground state and the field in its Fock state,the addition of oscillator makes the atomic population and atomic linear entropy different from the cosine oscillations in JC model.When the frequency of oscillator is equal to the dressed atom,both atomic population and linear entropy show the phenomenon of modulation.And the modulation frequency is determined by the oscillator occupancy and the coupling strength of oscillator and cavity field.With the increasing of oscillator occupancy or the coupling strength of oscillator and cavity field,the modulation frequency increases.The amplitudes of each envelope are also related to the oscillator occupancy and the coupling strength.If the oscillator frequency is adjusted so that the frequency is no longer equal to the dressed atom,an incomplete modulation phenomenon occurs.The amplitude and period of the modulation are related to the coupling strength between the oscillator and the cavity field,the number of photons and the frequency of the oscillator.For the coherent state of light field and ground state of atom,when the average photon number is small,the atomic population difference and linear entropy in JC model with quasi-periodic oscillation law are destroyed.In the case of atomic population,the increase in the number of vibrators leads to the suppression of the amplitude of the oscillator.For atomic linear entropy,the minimum value of linear entropy is increased with the increase of the oscillator occupied number,that is,the atom is gradually away from the pure state,and the maximum value of linear entropy increases with the increase of oscillator frequency,that is,the atom gradually approaches the maximum mixed state.We have also studied atomic emission spectra.The result shows that the symmetry of the atomic emission spectrum is destroyed by the addition of the movable mirror.When the coupling strength between the end mirror and the cavity field increases,the peak on the right side of the atomic emission spectrum is suppressed,while the left peak is enhanced.With the increase of m,the peak height of the left and right sides of the symmetry center is restrained,the splitting of the peaks will occur. |
