arXiv:cond-mat/9312083 · Physical review. B, Condensed matter
Luttinger liquid in a solvable two-dimensional model
R. Hlubina
Abstract
We consider spinless electrons in two dimensions with the bare spectrum ${\mathrm{\ensuremath{\epsilon}}}_{\mathbf{p}}$=${\mathit{v}}_{\mathit{F}}$(\ensuremath{\Vert}${\mathit{p}}_{\mathit{x}}$\ensuremath{\Vert}+\ensuremath{\Vert}${\mathit{p}}_{\mathit{y}}$\ensuremath{\Vert}). In momentum space, the interactions among electrons have a finite range ${\mathit{q}}_{0}$, which is small compared to the Fermi momentum. A golden-rule calculation of the electron lifetime indictes a breakdown of Landau's Fermi-liquid theory in the model. At the one-loop level of perturbation theory, we show that the density wave and the superconducting instabilities cancel each other and there is no symmetry breaking. We solve the model via bosonization; the excitation spectrum is found to consist of gapless bosonic modes as in a one-dimensional Luttinger liquid.