Quantum Monte Carlo and exact diagonalization study of a dynamic Hubbard model

Comparison of Calculations for the Hubbard model obtained with Quantum-Monte-Carlo, exact and stochastic Diagonalization

In this paper we compare numerical results for the ground state of the Hubbard model obtained by Quantum-Monte-Carlo simulations with results from exact and stochastic diagonalizations. We find good agreement for the ground state energy and superconducting correlations for both, the repulsive and attractive Hubbard model. Special emphasis lies on the superconducting correlations in the repulsiv...

Exact diagonalization and Quantum Monte Carlo studies of quantum dots

We report exact diagonalization and diffusion quantum Monte Carlo calculations of quantum dots (QDs) in which energetics due to electron-electron interactions, magnetic field, and geometrical factors compete and induce interesting ground state configurations. The geometrical effects are generated by different confining potentials such as parabolic shaped, ring shaped, and disordered potentials....

Classical and Quantum Monte Carlo Algorithms and Exact Diagonalization

Nuclear Shell Model by the Quantum Monte Carlo Diagonalization Method.

The feasibility of shell-model calculations is radically extended by the Quantum Monte Carlo Diagonalization method with various essential improvements. The major improvements are made in the sampling for the generation of shell-model basis vectors, and in the restoration of symmetries such as angular momentum and isospin. Consequently the level structure of low-lying states can be studied with...

Multiorbital Hubbard model in infinite dimensions: Quantum Monte Carlo calculation

Using the quantum Monte Carlo technique we compute thermodynamics and spectra for the orbitally degenerate Hubbard model in infinite spatial dimensions. With increasing orbital degeneracy we find in the one-particle spectra broader Hubbard bands ~consistent with increased kinetic energy!, a narrowing Mott gap, and increasing quasiparticle spectral weight. Hund’s rule exchange coupling decreases...