  We investigate the mechanism of heat conduction in ordered and disordered
harmonic onedimensional chains within the quantum mechanical Langevin method.
In the case of the disordered chains we find indications for normal heat
conduction which means that there is a finite temperature gradient but we
cannot clearly decide whether the heat resistance increases linearly with the
chain length. Furthermore we observe characteristic quantum mechanical features
like Bose-Einstein statistics of the occupation numbers of the normal modes,
freezing of the heat conductivity and the influence of the entanglement within
the chain on the current. For the ordered chain we recover some classical
results like a vanishing temperature gradient and a heat flux independent of
the length of the chain.
