DMRG evaluation of the Kubo formula —Conductance of strongly interacting quantum systems

Abstract

In this paper we present a novel approach combining linear response theory\n(Kubo) for the conductance and the Density Matrix Renormalization Group (DMRG).\nThe system considered is one-dimensional and consists of non-interacting tight\nbinding leads coupled to an interacting nanostructure via weak links. Electrons\nare treated as spinless fermions and two different correlation functions are\nused to evaluate the conductance.\n Exact diagonalization calculations in the non-interacting limit serve as a\nbenchmark for our combined Kubo and DMRG approach in this limit. Including both\nweak and strong interaction we present DMRG results for an extended\nnanostructure consisting of seven sites. For the strongly interacting structure\na simple explanation of the position of the resonances is given in terms of\nhard-core particles moving freely on a lattice of reduced size.\n