Article révisé par les pairs
| Résumé : | In previous papers 1,2), we have shown how to describe the approach to equilibrium of quantum systems in terms of energy conserving processes, these energies being those obtained in the Green's functions method. This is made possible by the use of non-unitary transformations diagonalizing the energy superoperator. This technique is now applied to the approach to equilibrium of a two-level system interacting with the electromagnetic field in the rotating wave approximation. Multiphoton processes are taken into account. It is quite remarkable that these multiphoton processes drive the system to canonical equilibrium, including the usual black-body distribution for radiation. This is a rather unexpected result as, in the Pauli approximation involving only one photon processes, equilibrium is only established between the "atom" and resonant photons (i.e. photons which energy is equal to the difference between the energies of the two atomic levels). © 1981. |
