Effects of internal and external decoherence on the resonant transport and Anderson localization of fermionic particles in disordered tight-binding chains

We study the effects of relaxation/decoherence processes on quantum transport of noninteracting Fermi particles across the disordered tight-binding chain, where we distinguish between relaxation processes in the contacts (external decoherence) and those in the chain (internal decoherence). It is shown that external decoherence reduces conductance fluctuations but does not alter the Anderson localization length. This is in strong contrast with the effect of internal decoherence which is found to suppress Anderson localization. We also address quantum transport in chains with particle losses which are of considerable interest for laboratory experiments with cold atoms.