We investigate the time development of a superposition of macroscopically distinct quantum states (Schrödinger cats) in an ensemble of two-level atoms. The system is interacting with a thermal environment of a macroscopic number of photon modes. The final equilibrium state of the atomic subsystem is diagonal in the energy eigenstates, and is determined by the Boltzmann distribution. The time scale of decoherence is, however, generally much shorter than that of dissipation. The initial fast regime of the time evolution associated with the decoherence is directed towards a classical state which is different from the thermal equilibrium. For general initial conditions the distance between the actual state of the system and this classical state is decreasing fast, suggesting an appropriate measure of decoherence.
|Number of pages||8|
|Journal||Acta Physica Slovaca|
|Publication status||Published - jún. 1 2000|
ASJC Scopus subject areas
- Physics and Astronomy(all)