Unified Quantum Mechanical Picture for Confined Spinons in Dimerized and Frustrated Spin S=1/2 Chains

TL;DR

This paper develops a unified quantum mechanical framework to describe confined spinons in S=1/2 chains, accounting for effects of dimerization and frustration, and provides detailed calculations of local magnetization, energies, and confinement lengths.

Contribution

It introduces a comprehensive model for confined spinons in various spin chains, extending previous ideas to weak or zero frustration scenarios.

Findings

Confined spinons are described by a nonlinear potential V(x)~|x|^b.

Local moments are enhanced by approximately 11/3 times.

Estimated excitation energies and confinement lengths are provided.

Abstract

A quantum mechanical picture is presented to describe the behavior of confined spinons in a variety of S=1/2 chains. The confinement is due to dimerization and frustration and it manifests itselfas a nonlinear potential V(x)~ |x|^b, centered at chain ends (b <= 1) or produced by modulation kinks (b > 1). The calculation extends to weak or zero frustration some previous ideas valid for spinons in strongly frustrated spin chains. The local magnetization patterns of the confined spinons are calculated. A (minimum) enhancement of the local moments of about 11/3 over a single S=1/2 is found. Estimates for excitation energies and binding lengths are obtained.