  We address two-level systems arranged in ring configurations affected by
static disorder. In particular we investigate the role of dephasing in the
transport of an excitation along the ring. We compare the efficiency of the
transfer process on isotropic rings and on biomimetic rings modelled according
to the structure of light-harvesting complexes. Our analysis provides a simple
but clear and interesting example of how an interplay between the coherent
dynamics of the system and the incoherent action of the environment can enhance
the transfer capabilities of disordered lattices.
