Squeezing in the Thermal Jaynes-Cummings Model

We have studied the influence of thermal photons on the symmetry between the field and atomic squeezing (SFAS) exposed in the resonant vacuum-field Jaynes-Cummings model with an initially coherent atom. We have shown that when the number of thermal photons (N_av) is less than 0.01, the SFAS is not sensitive to the presence of thermal photons; when N_av≥ 0.01, the broken SFAS can be seen; when N_av≥ 0.1, the squeezed atom cannot radiate a squeezed field any longer. Also, we have discussed the possibility of detection of the boken symmetry in superconducting maser cavity.