  We have determined the thermal conductance of a system consisting of a
two-level atom coupled to two quantum harmonic oscillators in contact with heat
reservoirs at distinct temperatures. The calculation of the heat flux as well
as the atomic population and the rate of entropy production are obtained by the
use of a quantum Fokker-Planck-Kramers equation and by a Lindblad master
equation. The calculations are performed for small values of the coupling
constant. The results coming from both approaches show that the conductance is
proportional to the coupling constant squared and that, at high temperatures,
it is proportional to the inverse of temperature.
