Stepwise introduction of model complexity in a generalized master   equation approach to time-dependent transport
  We demonstrate that with a stepwise introduction of complexity to a model of an electron system embedded in a photonic cavity and a carefully controlled stepwise truncation of the ensuing many-body space it is possible to describe the time-dependent transport of electrons through the system with a non-Markovian generalized quantum master equation. We show how this approach retains effects of an external magnetic field and the geometry of an anisotropic electronic system. The Coulomb interaction between the electrons and the full electromagnetic coupling between the electrons and the photons are treated in a non-perturbative way using "exact numerical diagonalization". 
Vidar Gudmundsson, Olafur Jonasson, Thorsten Arnold, Chi-Shung Tang,   Hsi-Sheng Goan, and Andrei Manolescu
cond-mat.mes-hall