Finite size effects and 2-string deviations in the spin-1 XXZ chains

TL;DR

This paper extends nonlinear integral equations to describe the excited states of the spin-1 XXZ chain in the attractive regime, analyzing conformal spectra, root configurations, and 2-string deviations.

Contribution

It generalizes previous NLIE formulations to the attractive regime and provides analytical calculations of the conformal spectrum and detailed analysis of root configurations.

Findings

Analytical conformal spectrum in the attractive regime

Characterization of root configurations in the thermodynamic limit

Analysis of 2-string deviations in excited states

Abstract

In an earlier work [1] J. Suzuki proposed a set of nonlinear integral equations (NLIE) to describe the excited state spectrum of the integrable spin-1 XXZ chain in its repulsive regime. In this paper we extend his equations for the attractive regime of the model, and calculate analytically the conformal spectrum of the spin chain. We also discuss the typical root configurations of the thermodynamic limit as well as the 2-string deviations of certain excited states of the model. Special objects appearing in the NLIE are also treated with special care.