Eliade Stefanescu - THE COLLISIONAL DECAY OF A FERMI SYSTEM INTERACTING WITH A MANY-MODE ELECTROMAGNETIC FIELD

Version 1

      Publication Details (including relevant citation   information):

      International Journal of Modern Physics E 9 (2000) 17-50.

      Abstract:

      We consider a system of Z fermions coupled to a dissipative   environment  through a two-body potential. We represent the   system in a basis of  single-particle, two-particle, …   Z-particle excitated states. Using a  procedure for   averaging the rapid oscillations of the reduced density    matrix in the interaction picture, the master equation of the   system  takes the form of a series expansion of powers of   the dissipative potential  matrix elements. The term of the   second-order describes single-particle  transitions, while   the higher-order terms correspond to correlated  transitions   of the system particles. For the second- and the   third-order  terms, we derive microscopic expressions of the   dissipative  coefficients. For dissipative systems, when the   state collectivity is  broken into pieces through quantum   diffusion, we use the quantum master  equation of the    second-order approximation. This equation satisfies basic   physical  conditions: particle conservation, Fermi–Dirac or   Bose–Einstein  distributions as asymptotic solutions of the   populations, and entropy increase. On this basis, the decay of a   Fermi system interacting with a  many-mode electromagnetic   field is described in terms of microscopic  quantities: the   matrix elements of the dissipative potential, the  densities   of the environment states, and the occupation probabilities   of  these states. A near-dipode–dipode interaction of the   system with other  neighbouring systems is taken into   account. In addition to the coupling  of the polarization   with the population, included in the usual  equations for   two-level systems as a non-linear detuning, in equations for   N-level systems two new couplings  of the polarizations   appear: a coupling due to the proximity potential,  and a   coupling due to the local field corrections, as a   renormalization  of the Rabi frequencies.

      Address (URL): http://www.worldscinet.com/ijmpe/09/0901/S0218301300000039.html