Results 51 to 60 of about 6,166 (163)
Extended Hubbard model on a honeycomb lattice
Physical Review BThe lack of both nesting and a van Hove singularity at half filling, together with the presence of Dirac cones makes the honeycomb lattice a special laboratory to explore strongly correlated phenomena. For instance, at zero temperature the repulsive [attractive] Hubbard model only undergoes a transition to an antiferromagnetic [$s$-wave superconducting
Welberth Kennedy +3 more
openaire +2 more sources
Symmetries and mean-field phases of the extended Hubbard model [PDF]
Physical Review B, 1995 The two-dimensional extended Hubbard model that includes a nearest- neighbor Heisenberg interaction is studied using a mean-field theory where quasiparticles are defined by an U(8) group of canonical transformations. The theory is a generalization of the ordinary BCS theory, and Balian and Werthamer's theory of He-3 that permits both broken gauge, spin
Eriksson, A. B. +2 more
openaire +3 more sources
Fidelity study of superconductivity in extended Hubbard models
Physical Review B, 2015 The Hubbard model with local on-site repulsion is generally thought to possess a superconducting ground-state for appropriate parameters, but the effects of more realistic long-range Coulomb interactions have not been studied extensively. We study the influence of these interactions on superconductivity by including nearest and next-nearest neighbor ...
Plonka, N. +4 more
openaire +3 more sources
Extended Bose-Hubbard models with ultracold magnetic atoms [PDF]
Science, 2016 Making magnetic atoms interact Two magnets interact with each other through a force that depends on the distance between them and on their mutual orientation. How do these long-range dipolar forces affect the behavior of a system of many magnets? Baier et al.
Simon Baier +8 more
openaire +3 more sources
SciPost PhysicsDeterminant Quantum Monte Carlo (DQMC) provides numerically exact solutions for strongly correlated fermionic systems but faces significant computational challenges with increasing system size. While submatrix updates were originally developed for Hirsch-
Fanjie Sun, Xiao Yan Xu
doaj +1 more source
Statistical properties of the spectrum of the extended Bose–Hubbard model [PDF]
Journal of Statistical Mechanics: Theory and Experiment, 2010 Motivated by the role that spectral properties play for the dynamical evolution of a quantum many-body system, we investigate the level spacing statistics of the extended Bose–Hubbard model. In particular, we focus on the distribution of the ratio of adjacent level spacings, useful at large interactions, to distinguish between chaotic and non-chaotic ...
Kollath, Corinna +3 more
openaire +5 more sources
Extended Gutzwiller wave function for the Hubbard-Holstein model [PDF]
Europhysics Letters (EPL), 2007 We introduce a new type of Gutzwiller variational wavefunction for correlated electrons coupled to phonons, able to treat on equal footing electronic and lattice degrees of freedom. We benchmark the wavefunction in the infinite-$U$ Hubbard-Holstein model away from half-filling on a Bethe lattice, where we can directly compare with exact results by ...
Barone P +4 more
openaire +7 more sources
Machine learning Hubbard parameters with equivariant neural networks
npj Computational MaterialsDensity-functional theory with extended Hubbard functionals (DFT + U + V) provides a robust framework to accurately describe complex materials containing transition-metal or rare-earth elements.
Martin Uhrin +4 more
doaj +1 more source
Non-Fermi liquids in the extended Hubbard model [PDF]
Journal of Physics: Condensed Matter, 1996 30 pages, REVTEX, 14 figures included. To appear in ``Non Fermi Liquid Physics'', J. Phys: Cond. Matt. (1997)
openaire +2 more sources
Crystals, 2018 The optical conductivity in the charge order phase is calculated in the two-dimensional extended Hubbard model describing an organic Dirac electron system α -(BEDT-TTF) 2 I 3 using the mean field theory and the Nakano-Kubo formula ...
Daigo Ohki +3 more
doaj +1 more source