Physics – Condensed Matter – Strongly Correlated Electrons
Scientific paper
2009-08-06
Phys. Rev. B 80, 245112 (2009)
Physics
Condensed Matter
Strongly Correlated Electrons
7 pages, 9 figures
Scientific paper
10.1103/PhysRevB.80.245112
Using the dynamical mean-field theory (DMFT) we study the paramagnetic phase of the Hubbard model with the density of states (DOS) corresponding to the three-dimensional cubic lattice and the two-dimensional square lattice, as well as a DOS with inverse square root singularity. We show that the electron correlations rapidly smooth out the square-root van Hove singularities (kinks) in the spectral function for the 3D lattice and that the Mott metal-insulator transition (MIT) as well as the magnetic-field-induced MIT differ only little from the well-known results for the Bethe lattice. The consequences of the logarithmic singularity in the DOS for the 2D lattice are more dramatic. At half filling, the divergence pinned at the Fermi level is not washed out, only its integrated weight decreases as the interaction is increased. While the Mott transition is still of the usual kind, the magnetic-field-induced MIT falls into a different universality class as there is no field-induced localization of quasiparticles. In the case of a power-law singularity in the DOS at the Fermi level, the power-law singularity persists in the presence of interaction, albeit with a different exponent, and the effective impurity model in the DMFT turns out to be a pseudo-gap Anderson impurity model with a hybridization function which vanishes at the Fermi level. The system is then a generalized Fermi liquid. At finite doping, regular Fermi liquid behavior is recovered.
Bonča Janez
Pruschke Thomas
Zitko Rok
No associations
LandOfFree
Van Hove singularities in the paramagnetic phase of the Hubbard model: a DMFT study does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Van Hove singularities in the paramagnetic phase of the Hubbard model: a DMFT study, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Van Hove singularities in the paramagnetic phase of the Hubbard model: a DMFT study will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-706124