Spin structure factors and valence-bond-solid states of the trimerized Heisenberg chains in a magnetic field

TL;DR

This study uses DMRG to analyze spin structure factors and magnetization plateaus in trimerized Heisenberg chains, revealing stable plateau states with specific correlations and proposing a valence-bond-solid state explanation.

Contribution

It provides a detailed DMRG analysis of magnetization plateaus and introduces an approximate wave function and valence-bond-solid picture for these states.

Findings

Plateau states exhibit three-peak static structure factors unaffected by magnetic field.

Spin correlation functions form a perfect sequence related to magnetization.

Valence-bond-solid states explain the origin and number of magnetization plateaus.

Abstract

By means of the density matrix renormalization group (DMRG) method, the static spin structure factors and the magnetization plateaus of the trimerized Heisenberg ferromagnet-ferromagnet-antiferromagnet and antiferromagnet-antiferromagnet-ferromagnet spin chains in the presence of a magnetic field are elaborately studied. It is found that in the plateau states, the static structure factor with three peaks does not vary with the external magnetic field as well as the exchange couplings; the spin correlation function behaves as a perfect sequence and has a simple relation with the magnetization per site. An approximate wave function for the plateau states is proposed, and a picture based on the valence-bond-solid states is presented in order to understand the origin and the total number of the magnetization plateaus, which are shown to be in agreement with the DMRG results.