Tracking the effects of interactions on spinons in gapless Heisenberg chains

TL;DR

This paper investigates how interactions influence spinon excitations in gapless Heisenberg spin-1/2 chains, providing exact calculations of the two-spinon structure factor across all anisotropy values, revealing the evolution from free to coupled chains.

Contribution

It offers an exact algebraic computation of the two-spinon structure factor for all anisotropies in the gapless regime, elucidating interaction effects on spinons in a strongly-correlated system.

Findings

Quantitative description of spinon behavior across interaction strengths

Explicit mapping of interaction effects on spinon excitations

Exact algebraic results for the structure factor in the gapless regime

Abstract

We consider the effects of interactions on the nature of spinon excitations in Heisenberg spin-1/2 chains. We explicitly compute the two-spinon part of the longitudinal structure factor of the infinite chain in zero field for all values of anisotropy in the gapless antiferromagnetic regime, via an exact algebraic approach. Our results allow us to quantitatively describe the behaviour of these fundamental excitations for cases ranging from free to fully coupled chains, thereby explicitly mapping the effects of `turning on the interactions' in a strongly-correlated system.