Thermodynamic limit and boundary energy of the SU(3) spin chain with non-diagonal boundary fields

TL;DR

This paper analyzes the thermodynamic limit and boundary energy of SU(3) spin chains with non-diagonal boundary fields, showing the inhomogeneous term's contribution vanishes, enabling boundary energy calculations for high-rank models.

Contribution

It demonstrates that the inhomogeneous term's effect on ground state energy vanishes in the thermodynamic limit, facilitating boundary energy calculations for SU(n) spin chains with non-diagonal boundaries.

Findings

Inhomogeneous term contribution vanishes in the thermodynamic limit.

Boundary energy can be explicitly calculated for SU(2) and SU(3) chains.

Method applicable to other high-rank models with non-diagonal boundary fields.

Abstract

We investigate the thermodynamic limit of the su(n)-invariant spin chain models with unparallel boundary fields. It is found that the contribution of the inhomogeneous term in the associated T-Q relation to the ground state energy does vanish in the thermodynamic limit. This fact allows us to calculate the boundary energy of the system. Taking the su(2) (or the XXX) spin chain and the su(3) spin chain as concrete examples, we have studied the corresponding boundary energies of the models. The method used in this paper can be generalized to study the thermodynamic properties and boundary energy of other high rank models with non-diagonal boundary fields.