Dynamics and non-equilibrium steady state in a system of coupled   harmonic oscillators
  A system of two coupled oscillators, each of them coupled to an independent reservoir, is analysed. The analytical solution of the non-rotating wave master equation is obtained in the high-temperature and weak coupling limits. No thermal entanglement is found in the high-temperature limit. In the weak coupling limit the system converges to an entangled non-equilibrium steady state. A critical temperature for the appearance of quantum correlations is found. 
A. Ghesqui\`ere, I. Sinayskiy and F. Petruccione
quant-ph