RG study of a non local sine-Gordon model

TL;DR

This paper investigates a non-local sine-Gordon model linked to many-body systems with scattering processes, analyzing how non locality influences spectral gaps using renormalization group methods.

Contribution

It introduces a non-local extension of the sine-Gordon model and derives its RG flow equations, highlighting the impact of non locality on spectral properties.

Findings

Non locality modifies the RG flow of couplings.

Spectral gap behavior is affected by non-local interactions.

Results differ from previous harmonic approximation predictions.

Abstract

We study a non local version of the sine-Gordon model connected to a many-body system with backward and umklapp scattering processes. Using renormalization group methods we derive the flow equations for the couplings and show how non locality affects the gap in the spectrum of charge-density excitations. We compare our results with previous predictions obtained through the self-consistent harmonic approximation.