Dispersion relations and speeds of sound in special sectors for the integrable chain with alternating spins

TL;DR

This paper analyzes dispersion relations and sound speeds in specific sectors of an integrable alternating spin chain, extending previous work on anisotropic chains with spins 1/2 and 1.

Contribution

It provides a detailed comparison of dispersion relations and calculates sound speeds near sector borders in an integrable spin chain with alternating spins.

Findings

Dispersion relations are characterized for sectors with infinite Fermi zones.

Sound speeds are calculated near sector borders where Fermi radii vanish or diverge.

Results enhance understanding of excitations in integrable spin chains.

Abstract

Based on our previous analysis \cite{doerfel3} of the anisotropic integrable chain consisting of spins $s=1/2$ and $s=1$ we compare the dispersion relations for the sectors with infinite Fermi zones. Further we calculate the speeds of sound for regions close to sector borders, where the Fermi radii either vanish or diverge, and compare the results.