Filling-Control Metal-Insulator Transition in the Hubbard Model Studied by the Operator Projection Method

Details Filling-Control Metal-Insulator Transition in the Hubbard Model Studied by the Operator Projection Method Filling-Control Metal-Insulator Transition in the Hubbard Model Studied by the Operator Projection Method

2001-07-13

arxiv.org/abs/cond-mat/0107291v2

J. Phys. Soc. Jpn. 70 (2001) 3998.

Physics

Condensed Matter

Strongly Correlated Electrons

33 pages, submitted to J. Phys. Soc. Jpn

Scientific paper

10.1143/JPSJ.70.3398

Thermodynamic and dynamical properties of filling-control metal-insulator transition (MIT) in the Hubbard model are studied by the operator projection method, especially in two dimensions. This is a non-perturbative analytic approach to many-body systems. The present theory incorporates the Mott-Hubbard, Brinkman-Rice and Slater pictures of the MIT into a unified framework, together with reproducing low-energy narrow band arising from spin-charge fluctuations. At half filling, single-particle spectra $A(\omega, k)$ show formation of two Hubbard bands and their antiferromagnetic shadows separated by a Mott gap in the plane of energy $\omega$ and momentum $k$ with lowering temperatures. These four bands produce splitting to two low-energy narrow bands and two SDW-like bands in the dispersion. Near half filling, the low-energy narrow band persists at low temperatures. This narrow band has a particularly weak dispersion and large weights around $(\pi, 0)$ and $(0, \pi)$ momenta. The velocity of these low-energy excitations is shown to vanish towards the MIT, indicating the mass divergence as in the Brinkman-Rice picture, but most prominently around $(\pi,0)$ and $(0,\pi)$ with strong momentum dependence. This reflects the suppression of the coherence near the MIT. Main structures in $A(\omega, k)$ show remarkable similarities to quantum Monte-Carlo results in two dimensions as well as in the one-dimensional Hubbard model. The charge compressibility appears to diverge with decreasing doping concentration in both one and two dimensions in agreement with the exact and quantum Monte-Carlo results. We also discuss implications of the flat dispersion formed near the Fermi level to the observations in high-$\Tc$ cuprate superconductors.

Affiliated with

Also associated with

No associations

Rating

Filling-Control Metal-Insulator Transition in the Hubbard Model Studied by the Operator Projection Method 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 Filling-Control Metal-Insulator Transition in the Hubbard Model Studied by the Operator Projection Method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Filling-Control Metal-Insulator Transition in the Hubbard Model Studied by the Operator Projection Method will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-140942