Decoherence of Macroscopic States at Finite Temperatures

We study the macroscopic superposition of light coherent states of the type Schrodinger cat states; analizying, in particular, the role of the temperature in the decoherence processes, characteristic of the superposition of macroscopic states. The method we use here is based on the Master equation formalism, introducing an original approach. We use a modified Mandel function that is well adapted to the problem. This work is motivated by the experiments proposed by S. Haroche and collaborators in the 90's. In these experiments two Rydberg atoms were sent to a cavity in which a coherent state had been previously injected, monitoring the decay of quantum states due to dissipation. We find Haroche and collaborator's result at zero temperature and we predict the behavior of the field states in the cavity at finite temperatures.