Dynamic structure factor of disordered quantum spin ladders

TL;DR

This paper studies how quenched disorder affects the dynamical correlation functions in two-leg quantum spin ladders, revealing significant localization effects and quantum structures observable in experiments.

Contribution

It introduces a combined approach using perturbative continuous unitary transformations, white graphs, and bond-operator mean-field theory to analyze disorder effects.

Findings

Disorder causes localization of quasi-particles and bound states.

Significant alterations in dynamical structure factors due to disorder.

Observable quantum structures in spectroscopic experiments.

Abstract

We investigate the impact of quenched disorder on the dynamical correlation functions of two-leg quantum spin ladders. Perturbative continuous unitary transformations with the help of white graphs and bond-operator mean-field theory are used to calculate the one- and two-triplon contribution of the zero-temperature dynamical structure factor. Disorder results in huge effects on quasi-particles as well as composite bound states due to localization. This leads to intriguing quantum structures in dynamical correlation functions well observable in spectroscopic experiments.