Dynamical Structure Factors for the Heisenberg Chain with Alternating Exchange

TL;DR

This paper analyzes the dynamical structure factors of the Heisenberg chain with alternating exchange, revealing how higher-order interactions significantly alter the wave vector dependence compared to simple approximations.

Contribution

It provides a detailed series expansion analysis of transition strengths in the Heisenberg chain with alternating exchange up to tenth order, highlighting modifications in wave vector dependence.

Findings

Wave vector dependence is strongly modified in higher orders.

Series expansions up to tenth order improve understanding of transition strengths.

Simple dimer approximation is insufficient at higher orders.

Abstract

We discuss the transition strength between the disordered ground state and the basic low-lying triplet excitation for the Heisenberg chain with alternating exchange based on series expansions in the interdimer interaction up to tenth order. We demonstrate that the wave vector dependence of the simple dimer approximation is strongly modified in higher orders.