Adjacent face scattering of electrons on a square Fermi surface

TL;DR

This paper examines the stability of a square Fermi surface with interacting electrons, revealing its instability to doping without a spin gap under Hubbard interactions, using a bosonic framework.

Contribution

It introduces a bosonic approach to analyze electron scattering on a square Fermi surface, highlighting instability conditions not previously identified.

Findings

Square Fermi surface is unstable to doping without a spin gap.

Bosonic classification of fermion operators used for stability analysis.

Contrasts with earlier studies by showing instability under certain conditions.

Abstract

Interacting electrons with a square Fermi surface is investigated from a bosonic point of view taking into account electron scattering between all faces of the square. Fermion operators are classified according to their dimensions and the stability of the boson fixed-point is investigated. In particular we find, in contrast to previous studies, that the square Fermi surface is unstable to doping in the case of no spin gap and microscopic Hubbard interactions.