Magnon mode truncation in a rung-dimerized asymmetric spin ladder

TL;DR

This paper introduces an exactly solvable model for an asymmetric spin ladder with dimerized rungs, explaining magnon mode truncation due to decay, and relating it to experimental observations in a specific compound.

Contribution

The paper presents a new exactly solvable model that describes magnon mode truncation in an asymmetric spin ladder, linking theoretical parameters to experimental data.

Findings

Magnon mode truncation explained by the model

Relations established between model parameters and experimental quantities

Structure factor vanishes at the truncation point

Abstract

An exactly solvable effective model is suggested for an asymmetric spin ladder with dimerized rungs. Magnon mode truncation originated from magnon decay (recently observed in the 1D compound ${\rm IPA-CuCl}_3$) is naturally described within this model. Using Bethe Ansatze we described a one-magnon sector and obtained relations between interaction constants of the model and experimentally observable quantities such as the gap and truncation energies, spin velocity and the truncation wave vector. It is also shown that structure factor turns to zero at the truncation point.