0 A Density Matrix Renormalization Group study of Excitons in Dendrimers

We introduce the density matrix renormalization group (DMRG) method as an efficient computational tool for one-exciton approximations with off-diagonal disorder. This method allows us to reduce the computational effort by targetting only a few low-lying eigenstates at each statistical samplings, in contrast to the exact diagonalization methods that compute the whole spectrum. As an application of the method, we study excitons in two families of branched molecules called dendrimers using a recently introduced simple model. We compute the ab-sortion peaks for these dendrimers varying their generation number g and number of wedges w.