Soliton Approach to Spin-Peierls Antiferromagnets: Large-Scale Numerical Results

TL;DR

This paper investigates the behavior of spin-Peierls antiferromagnets by modeling elementary excitations as S=1/2 solitons, analyzing their interactions, bound states, and effects of interchain coupling through large-scale numerical simulations.

Contribution

It introduces a numerical study of soliton dynamics and bound states in spin-Peierls antiferromagnets considering interchain coupling effects.

Findings

Solitons are repelled by impurities in one-dimensional systems.

Interchain coupling influences the number of bound states.

Numerical results support the confining potential model.

Abstract

A simple intuitive picture of spin-Peierls antiferromagnets arises from regarding the elementary excitations as S=1/2 solitons. In a strictly one-dimensional system these excitations are assumed not to form bound-states and to be repelled by impurities. Couplings to the three-dimensional lattice are assumed to produce an effective confining potential which binds solitons to antisolitons and to impurities, with the number of bound-states increasing as the interchain coupling goes to 0. We investigate these various assumptions numerically in a phononless model where spontaneous dimerization arises from frustration and the interchain coupling is treated in mean field theory.