Finite Temperature Dynamical Structure Factor of Alternating Heisenberg Chains

TL;DR

This paper develops a low-temperature expansion method to analyze the finite temperature dynamical structure factor of alternating Heisenberg chains, focusing on line broadening and thermal scattering effects.

Contribution

It introduces a novel low-temperature expansion approach for the dynamical structure factor in alternating Heisenberg chains, emphasizing strong alternation limits.

Findings

Characterizes broadening of low-lying triplet lines.

Analyzes thermally activated intraband scattering.

Provides insights into finite temperature effects on spin chains.

Abstract

We develop a low-temperature expansion for the finite temperature dynamical structure factor of the spin half Heisenberg chain with alternating nearest neighbour exchange in the limit of strong alternation of the exchange constants. We determine both the broadening of the low lying triplet lines and the contribution of the thermally activated intraband scattering.