The Electron Green's Function for the t-t'-J Model in 1,2 … ∞ Dimensions

By combining the extremely correlated Fermi liquid (ECFL) theory and the density matrix renormalization group (DMRG) method, we present an overview of the electron propagator of the t-t'-J model in any dimension for various parameters of the model and electron densities. In 1-d the DMRG method gives essentially exact numerical results, which are shown to compare quite well with the ECFL method. In particular, the momentum dependence can be checked against the exact DMRG result. We use a closed set of equations from ECFL theory that are valid in all dimensions. Their application to infinite dimension has been checked against dynamical mean field theory earlier. These equations have also been applied to recently 2-d. The present study fills the remaining gap, thus giving an overview of the solution in all dimensions. In 1-d at low energies, we find clear signatures of spin-charge separation in both calculations. At higher energies, the spectral functions resemble those in higher dimensions.