Abstract

We have calculated (both, analytically¹ and by computer) the Q-function (quasiprobability distribution in the field phase space) for a system of N two-level atoms interacting with the quantum e.m. field in a lossless cavity. For the one atom case the analogous problem has been solved in the work.² The field was supposed to be initially in a coherent state. For arbitrary initial atomic state, the Q-function has N+1 humps of Gaussian form. When all these humps are essentially separated in the phase space the photon number and atomic inversion oscillations are collapsed. If some of the humps overlap it results in the oscillations revival. We have found N+1 initial atomic states for which the system wave function is approximately factorized into the product of the field and atomic wave functions. The atomic entropy has been calculated in order to estimate the accuracy of this factorization.

© 1993 Optical Society of America