Breakdown of Luttinger liquid state in one-dimensional frustrated spinless fermion model

TL;DR

This paper investigates the limits of Luttinger liquid theory in a 1D spinless fermion model with frustration, revealing conditions where the ground state remains gapless but deviates from LL behavior.

Contribution

It demonstrates numerically that strong interactions and frustration can produce gapless states that are not Luttinger liquids, challenging the universality hypothesis.

Findings

Large interactions lead to non-LL gapless states

Correlation exponents differ from standard LL predictions

Frustration induces metallic states outside LL framework

Abstract

Haldane hypothesis about the universality of Luttinger liquid (LL) behavior in conducting one-dimensional (1D) fermion systems is checked numerically for spinless fermion model with next-nearest-neighbor interactions. It is shown that for large enough interactions the ground state can be gapless (metallic) due to frustrations but not be LL. The exponents of correlation functions for this unusual conducting state are found numerically by finite-size method.