Metal to Insulator Transition in the 2-D Hubbard Model: A Slave Boson Approach

1996/03/18 by Raymond Fresard, Klaus Doll
Physics and Astronomy · #cond-mat

paper · pdf

published as published in 'The Hubbard Model: Its Physics and Mathematical Physics' (Editors: D. Baeriswyl, D. K. Campbell, J. M. P. Carmelo, F. Guinea, E. Louis), Plenum Press 1995, p. 385-392 · 8 pages, postscript

arxiv created 1996/03/18 · arxiv updated 2009/11/30

Abstract

We use the Kotliar-Ruckenstein slave boson technique to treat the strong correlation of the Hubbard model. In a first part we discuss the metal to insulator transition that is occurring on the honeycomb lattice at half filling. We find the critical value for the interaction strength to be U/t=3.1. Above it a gap opens in the spectrum which behaves like (U-U_c) in the vicinity of the transition, and like U for strong coupling. In a second part we calculate the phase diagram of the Hubbard model on the square lattice at finite temperature. The Mermin-Wagner theorem is fulfilled in the largest part of the phase diagram. In the strong coupling regime, the uniform magnetic susceptibility shows a maximum in its doping dependence in agreement with numerical simulations.

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