Frustration-induced eta inversion in the S=1/2 bond-alternating spin chain

TL;DR

This paper investigates how frustration enhances incommensurate correlations in a bond-alternating S=1/2 spin chain under magnetic field, revealing temperature-dependent behaviors and potential for field-induced order.

Contribution

It demonstrates the frustration-induced enhancement of incommensurate correlations and explores the mechanism via mapping to an effective XXZ chain.

Findings

Incommensurate correlation becomes dominant in certain magnetic field ranges.

Temperature affects the staggered susceptibilities and correlation dominance.

Possible field-induced incommensurate long-range order is discussed.

Abstract

We study the frustration-induced enhancement of the incommensurate correlation for a bond-alternating quantum spin chain in a magnetic field, which is associated with a quasi-one-dimensional organic compound F5PNN. We investigate the temperature dependence of the staggered susceptibilities by using the density matrix renormalization group, and then find that the incommensurate correlation becomes dominant in a certain range of the magnetic field. We also discuss the mechanism of this enhancement on the basis of the mapping to the effective S=1/2 XXZ chain and a possibility of the field-induced incommensurate long range order.