Geometrical non-Abelian bosonization approach for the two-dimensional Hubbard model.

Abstract

A geometrical non-Abelian bosonization for the Fermi surface excitations is constructed. We introduce a unitary operator which generates the deformation of the Fermi surface which obeys non-Abelian Kac-Moody-Poisson brackets. We study the Hubbard model for d\ensuremath{\ge}1, the charge part is a Fermi liquid at finite temperature and a Luttinger liquid for d=1 at T=0. The spin part is described by an 0(3) nonlinear sigma model. \textcopyright{} 1996 The American Physical Society.