Jaynes-Cummings-model with damping at resonance

The time evolution of a damped two-level atom coupled to a damped field mod e at resonance is calculated analytically as well as numerically in the bas is of dressed states. We study the dynamics of the density matrix and of ob servables, e.g. the number of field quanta. For the initial states we consi der the field to be in a Fock or Glauber state and the atom in the ground o r excited state. We show the significant influence of the damping oil the w ell-known phenomena of this model. e.g. collapse and revival.