Mott metal-insulator transition in the Hubbard model

Details Mott metal-insulator transition in the Hubbard model Mott metal-insulator transition in the Hubbard model

2007-07-02

arxiv.org/abs/0707.0142v1

Physics

Condensed Matter

Strongly Correlated Electrons

13 pages, 1 figure

Scientific paper

The Hubbard model in the strong-coupling regime is mainly studied by Kondo-lattice theory or 1/d expansion theory, with d the spatial dimensionality. In two dimensions and higher, the ground state within the Hilbert subspace with no order parameter is a normal Fermi liquid except for n=1 and U/W=+infinity, with n the electron density per unit cell, U the on-site repulsion, and W the bandwidth; the cooperation between the Kondo effect, which favors a local singlet on each unit cell, and a resonating-valence-bond effect, which favors a local singlet on each pair of nearest-neighbor unit cells, stabilizes the Fermi liquid, whose ground state is a singlet as a whole, in the strong-coupling regime. In the whole Hilbert space with no restriction, the normal Fermi liquid is unstable at least against a magnetic or superconducting state. This analysis confirms an early Fermi-liquid theory of high-temperature superconductivity, F. J. Ohkawa, Jpn. J. Appl. Phys. 26, L652 (1987). The ground state for n=1 and U/W=+infinity is a Mott insulator. Actual metal-insulator transitions cannot be explained within the Hubbard model. In order to explain them, the electron-phonon interaction, multi-band or multi-orbital effects, and effects of disorder should be considered beyond the Hubbard model. The crossover between local-moment magnetism and itinerant-electron magnetism corresponds to that between a localized spin and a normal Fermi liquid in the Kondo effect and it is simply a Mott metal-insulator crossover.

Affiliated with

Also associated with

No associations

Rating

Mott metal-insulator transition in the Hubbard model 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 Mott metal-insulator transition in the Hubbard model, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Mott metal-insulator transition in the Hubbard model will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-692344