相关论文: Stability of correlated electronic systems under t…

The Holstein Hubbard and Holstein t--J models are studied for a wide range of phonon frequencies, electron--electron and electron--phonon interaction strengths on finite lattices with up to ten sites by means of direct Lanczos…

We study by exact diagonalization the two-dimensional t-J-Holstein model near quarter filling by retaining only few phonon modes in momentum space. This truncation allows us to incorporate the full dynamics of the retained phonon modes. The…

Ground-state and dynamical properties of the 2D Holstein t-J model are examined by means of direct Lanczos diagonalization, using a truncation method of the phononic Hilbert space. The single-hole spectral function shows the formation of a…

We study the role of non-adiabatic Holstein electron-phonon coupling on the neutral-ionic phase transition of charge transfer crystals which can be tuned from continuous to discontinuous, using exact numerical diagonalization. The variation…

We propose a numerical method which embeds the variational non-Gaussian wavefunction approach within exact diagonalization, allowing for efficient treatment of correlated systems with both electron-electron and electron-phonon interactions.…

An optimized phonon approach for the numerical diagonalization of interacting electron-phonon systems is proposed. The variational method is based on an expansion in coherent states that leads to a dramatic truncation in the phonon space.…

We investigate the interplay of electron-phonon (EP) coupling and strong electronic correlations in the frame of the two-dimensional (2D) Holstein t-J model (HtJM), focusing on polaronic ordering phenomena for the quarter-filled band case.…

The one-dimensional (1D) $t$-$J$ Holstein model is studied by exact diagonalization of finite rings using a variational approximation for the phonon states. Due to renormalization effects induced by the phonons, for intermediate…

We propose a new optimized phonon approach for the numerical diagonalization of interacting electron-phonon systems combining density-matrix and Lanczos algorithms. We demonstrate the reliablity of this approach by calculating the phase…

We consider the Hubbard-Holstein model in the adiabatic limit to investigate the effects of electron-electron interactions on the electron-phonon coupling. To this aim we compute at any momentum and filling the static charge susceptibility…

We consider a model Hamiltonian for a dimer including all the electronic one- and two-body terms consistent with a single orbital per site, a free Einstein phonon term, and an electron-phonon coupling of the Holstein type. The bare…

Studies of Hamiltonians modeling the coupling between electrons as well as to local phonon excitations have been fundamental in capturing the novel ordering seen in many quasi-one dimensional condensed matter systems. Extending studies of…

The Hubbard-Holstein model is a simple model including both electron-phonon interaction and electron-electron correlations. We review a body of theoretical work investigating the effects of strong correlations on the electron-phonon…

An exact diagonalization technique is used to investigate the low-lying excited polaron states in the Holstein model for the infinite one-dimensional lattice. For moderate values of the adiabatic ratio, a new and comprehensive picture,…

We study the effect of diagonal and off-diagonal electron-phonon coupling in the ground state properties of the t-J model. Adiabatic and quantum phonons are considered using Lanczos techniques. Charge tiles and stripe phases with mobile…

We study the Hubbard-Holstein model using slave-boson mean-field and a variation al Lang-Firsov transformation. We identify weak and strong e-ph coupling solutions, whose stability depends both on the bare e-ph coupling and on the…

The Hubbard-Holstein model is one of the central models that describe the competition between electron-electron and electron-phonon interactions. In one dimension and at half-filling, the interplay between an electronic spin-density wave…

We present numerical exact results for the polaronic band structure of the Holstein molecular crystal model in one and two dimensions. The use of direct Lanczos diagonalization technique, preserving the full dynamics and quantum nature of…

We investigate, by numerically calculating the charge stiffness, the effects of random diagonal disorder and electron-electron interaction on the nature of the ground state in the 2D Hubbard model through the finite size exact…

Self-localization of holes in the Holstein t-J model is studied in the adiabatic limit using exact diagonalization and the retraceable path approximation. It is shown that the critical electron-phonon coupling \lambda_c decreases with…