Results 221 to 230 of about 19,877 (264)

Disorder and interactions in the Hubbard model

Physical Review Letters, 1989
We investigate the single-band repulsive Hubbard model with random site energies as a model for the disordered electron system in the strong-interaction limit. Previous scaling treatments of this problem, pioneered by Finkel’shtein, are based on a perturbative treatment of the interactions and the scaling eventually fails as the couplings become large.
, Zimanyi, , Abrahams
openaire   +2 more sources

Band magnetism in the Hubbard model

Physical Review B, 1989
A self-consistent moment method is applied to the Hubbard model in order to find out under what circumstances spontaneous band magnetism may occur. The theory is formulated for a two-sublattice structure to treat simultaneously para-, ferro-, and antiferromagnetic systems.
Nolting, W., Borgiel, W.
openaire   +3 more sources

THE HUBBARD-STRATONOVICH TRANSFORMATION AND THE HUBBARD MODEL

International Journal of Modern Physics B, 1991
The Hubbard-Stratonovich transformation allows one to formulate the problem of calculating the ground state properties of a many-body theory as one of sampling a distribution. This distribution is constructed by propagating a trial wave function under the influence of a one-body time-dependent external field.
openaire   +2 more sources

A Model for Crystallization: A Variation on the Hubbard Model

Physica A: Statistical Mechanics and its Applications, 1986
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
openaire   +1 more source

Two Theorems on the Hubbard Model

Physical Review Letters, 1989
In the attractive Hubbard model (and some extended versions of it) the ground state is proved to have spin angular momentum S = 0 for every (even) electron filling. In the repulsive case, and with a bipartite lattice and a half filled band, the ground state has S = 1/2∥B∣ − ∣A∥, where ∣B∣ (resp. ∣A∣) is the number of sites in the B (resp. A) sublattice.
openaire   +2 more sources

Entanglement, Hubbard Model, and Symmetries

International Journal of Theoretical Physics, 2004
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Hardy, Yorick, Steeb, Willi-Hans
openaire   +2 more sources

Hubbard model for a cubic cluster

Physical Review B, 1987
The ground-state and thermodynamic properties of a simple Hubbard Hamiltonian are studied for an eight-site cubic cluster as functions of the number of electrons and the strength of the electron interaction. The ground-state energy and spin are determined, and the excitation spectrum is computed.
, Callaway, , Chen, , Zhang
openaire   +2 more sources

Phase separation in the Hubbard model

Physical Review B, 1993
We use the correlated-random-field approximation and a conditional coherent-potential approximation to study the ground-state phase diagram of the one-band Hubbard model. Our approach incorporates both spin and electron correlations. It has been found that for certain values of the parameters of the model, in addition to paramagnetic, ferromagnetic ...
, Andriotis, , Economou, , Li, , Soukoulis   +3 more
openaire   +2 more sources

The Hubbard Model

1991
This collection of articles provides authoritative and up-to-date reviews on the Hubbard Model. It will be useful to graduate students and researchers in the field.
openaire   +1 more source

Constraints on pairings in the Hubbard model

Physical Review B, 1995
Pairing operators of electrons with an arbitrary distance on a square lattice are defined in each possible wave channel, {ital s}, {ital p}, {ital d}{sub {ital x}}{sup 2}{minus}{ital y}{sup 2}, {ital d}{sub {ital x}{ital y}}, and {ital g}{sub {ital x}}{sup 3}{ital y}{minus}{ital xy}{sup 3}. Exact identities among pairing amplitudes in the Hubbard model
openaire   +2 more sources