  The quantum dynamics of a spin chain interacting with multiple bosonic baths
is described in a mixed Wigner-Heisenberg representation. The formalism is
illustrated by simulating the time evolution of the reduced density matrix of
two coupled spins, where each spin is also coupled to its own bath of harmonic
oscillators. In order to prove the validity of the approach, an analytical
solution in the Born-Markov approximation is found. The agreement between the
two methods is shown.
